,  LOCOMOTIVE-  ,: 


INCLUDING 


A  DESCRIPTION  OF  ITS  STRUCTURE, 
RULES  FOR  ESTIMATING  ITS  CAPABILITIES. 

AND 

PRACTICAL  OBSERVATIONS  ON  ITS  CONSTRUCTION  AND 
MANAGEMENT. 


BY  ZERAKJ10LBURN. 

OP  THE      "$? 


PHILADELPHIA: 
HENRY     CAREY     BAIRD, 

INDUSTRIAL     PUBLISHER, 

No.    406    WALNUT    STREET. 

1873. 


Entered  according  to  Act  of  Congress,  in  the  year  1851,  by 

REDDING  AND  COMPANY, 
in  the  Clerk's  Office  of  the  District  Court  for  the  District  of  Massachusetts. 


STEREOTYPED  BY  L.  JOHNSON  t  CO. 
PHILADELPHIA. 


Planted  by 


INTRODUCTORY  NOTICE. 


THE  absence  of  any  purely  practical  work 
on  American  locomotives  has  induced  the 
preparation  of  the  following  pages  devoted 
to  that  subject.  It  is  believed  the  book  will 
afford  to  the  student  a  clear  idea  of  the 
nature  and  mode  of  application  of  steam 
power,  while  to  those  engaged  in  the  manu- 
facture and  operation  of  engines  it  will 
afford  much  useful  matter  connected  with 
their  construction  and  management. 

Much  care  has  been  bestowed  to  render 
plain  and  distinct  those  parts  of  the  book 
which  are  devoted  to  the  principles  of 


4  INTRODUCTORY    NOTICE. 

locomotive  science ;  and  the  rules  and 
illustrations  have  been  adapted  to  the 
wants  of  those  who  have  but  little  time 
or  taste  for  the  pursuit  of  abstract  in- 
vestigations. While  this  feature  will  con- 
stitute a  chief  merit  of  the  work  in  the 
hands  of  such  persons,  it  will  make  it 
none  the  less  definite  and  exact  for  the 
purposes  of  the  designer  and  engineer. 

The  particulars  of  many  recent  engines, 
and  improvements  connected  therewith,  have 
been  presented,  embracing  the  patterns  of 
a  majority  of  all  the  Hiilders  in  the  United 
States.  For  many  of  these  we  are  indebted 
to  the  manufacturers  of  engines,  while 
others  have  been  procured  for  the  purpose 
from  the  engines  themselves — those  ma- 
chines being  selected  which  presented  some 
new  or  favourable  feature  in  the  proportions 
of  their  parts  or  in  the  arrangement  of  their 
machinery. 

It  is  therefore  hoped  that  the  book  may 


INTRODUCTORY   NOTICE.  5 

impart  some  benefit  to  those  who  read  it, 
and  that  it  may  serve  to  this  purpose  until 
the  appearance  of  a  better  one  from  those 
whose  opportunities  for  information  would 
enable  them  to  treat  the  subject  in  a  man- 
ner more  suited  to  the  various  requirements 
of  its  nature. 


CONTENTS. 


SECTION  I. 

The  Properties   of  Steam   and  the   Phenomena  con- 
nected with  its  Generation Page      9 

SECTION  II. 

A  general  Description  of  the  Construction  of  the  Lo- 
comotive Engine 22 

SECTION  III. 

Details  of  the  Locomotive  Ja>yine.  —  The  Boiler  and 
its  Appendages ,v 39 

SECTION  IV. 

Details  of  the  Locomotive  Engine  continued.— Of  the 
Cylinders,  Steam  Chests,  Valves,  and  Steam  Pipes.  62 

SECTION  V. 

Details  of  the  Locomotive  Engine  continued  —Of  the 
Framing,  Jaws,  Wheels,  Springs,  &c 68 

SECTION  VI. 

Details  of  the  Locomotive  Engine  continued. — Of  the 
Pistons,  Slides,  Connecting  Kods,  Valve  Motion, 
and  Pumps 78 

7 


8  CONTENTS. 

- 

SECTION  VIT. 
Remarks  on  the  Management  of  Engines....! Paye    97 

SECTION  VIII. 
Various  Patterns  of  Locomotives 108 

SECTION  IX. 
Tables  and  Calculations  relative  to  the  Locomotive...  127 

SECTION  X. 
Miscellaneous  Notes  and  Observations 155 

A  GLOSSARY  OF  TERMS  applied  to  the  Machinery,  and 
to  the  Operation  of  the  Locomotive  Engine 171 

,  ,.  181 


THE 


LOCOMOTIVE  ENGINE, 


SECTION  I. 

THE   PROPERTIES    OF   STEAM  AND  THE  PHENOMENA 
CONNECTED   WITH   ITS    GENERATION. 

THE  most  prominent  of  the  properties  pos- 
sessed by  steam  are  its  high  expansive  force, 
its  property  of  condensation  by  an  abstraction 
of  its  temperature,  its  concealed  or  undeveloped 
heat,  and  the  inverted  ratio  of  its  pressure  to 
the  space  which  it  occupies. 

Steam  is  the  result  of  a  combination  of  water 
with  a  certain  amount  of  heat ;  and  the  expan- 
sive force  of  steam  arises  from  the  absence  of 
cohesion  between  and  among  the  particles  of 
water.  Heat  universally  expands  all  matter 


10  THE    LOCOMOTIVE    ENGINE. 

within  its  influence,  whether  solid  or  fluid;  but 
in  a  solid  body  it  has  the  cohesion  of  the  par- 
ticles to  overcome,  and  this  so  circumscribes  its 
effects  that  in  cast-iron,  for  instance,  a  rate  of 
temperature  above  the  freezing  point  sufficient 
to  melt  it,  causes  an  extension  of  only  about 
one-eighth  of  an  inch  in  a  foot.  With  water, 
however,  a  temperature  of  212°,  or  180°  above 
the  freezing  point,  (and  which  is  far  from  a  red- 
heat,)  converts  it  into  steam  of  1700  times  its 
original  bulk  or  volume. 

All  bodies  may  exist  in  either  one  or  all  of 
three  different  states,  viz.  the  solid  state,  the 
liquid  state,  and  the  aeriform  state,  or  state  of 
vapour.  Water,  for  example,  may  exist  as  ice, 
liquid,  and  steam ;  and  the  condition  which  it 
assumes  depends  on  its  pervading  temperature. 

Steam  cannot  mix  with  air  while  its  pressure 
exceeds  that  of  the  atmosphere,  and  it  is  this 
property,  with  that  which  makes  the  condition 
of  a  body  dependent  on  its  temperature,  that 
explains  the  condensing  property  of  steam.  In 
a  cylinder  once  filled  with  steam  of  a  pressure 
of  15  Ibs.  or  more  to  the  square  inch,  all  air  is 
excluded.  Now  as  the  existence  of  the  steam 


THE    LOCOMOTIVE    ENGINE.  11 

depends  on  its  temperature,  by  abstracting  that 
temperature  (which  may  be  done  by  immersing 
the  cylinder  in  cold  water  or  in  cold  air)  the 
contained  steam  assumes  the  state  due  to  the 
reduced  temperature,  and  this  state  will  be 
water.  And,  as  the  water  cannot  occupy  the 
volume  which  it  did  under  its  former  tempera- 
ture, it  follows  that  its  reduction  in  volume 
must  remain  a  vacuum.  A  cylinder,  therefore, 
filled  with  hot  steam,  may  be  condensed  by  an 
abstraction  of  its  heat,  and  a  vacuum  will  be 
produced  in  the  cylinder  with  a  few  drops  of 
water  at  the  bottom,  which  may  be  pumped  out 
by  an  air-tight  pump,  leaving  the  vacuum  per- 
fect. 

When  this  principle  is  employed  in  removing 
the  atmospheric  pressure  opposed  to  the  back 
of  the  piston  in  a  steam  engine,  such  an  engine 
is  termed  a  condensing  engine :  and  in  such 
engines  more  work  may  be  done  with  the  same 
pressure  of  steam  than  by  a  non-condensing 
engine,  as  the  absence  of  the  weight  of  the  air, 
or  the  negative  pressure  on  the  back  of  the 
piston  is  equivalent  to  a  positive  pressure  on  the 
other  side,  and  contributes  by  so  much  to  the 


12  THE    LOCOMOTIVE    ENGINE. 

useful  effect  of  the  engine.  Locomotive  engines, 
however,  and  most  American  stationary  engines, 
discharge  their  steam  without  condensing,  and  to 
overcome  the  atmospheric  resistance  they  carry 
higher  steam;  they  are  therefore  called  high- 
pressure  engines. 

The  next  property  of  steam  which  we  have 
mentioned  is  that  of  its  latent  or  concealed 
heat.  An  unknown  amount  of  latent  heat  exists 
in  every  element  in  nature :  thus,  iron  becomes 
hot  by  merely  hammering  it  on  an  anvil;  air 
gives  off  heat  enough  to  light  fire  by  being  com- 
pressed into  a  syringe,  and  so  on.  The  beating 
of  the  iron  does  not  create  the  heat  which  it 
excites,  neither  does  the  compressing  of  the  air ; 
they  both  merely  develop  the  heat,  which  must 
have  a  previous  existence.  In  these  examples, 
the  heat  which  is  excited  is  freed  by  the  motion 
communicated, — and  we  have  no  means  of  know- 
ing its  amount;  but  the  latent  heat  of  steam, 
though  showing  no  effects  on  the  thermometer, 
may  be  as  easily  known  as  the  sensible  or  per- 
ceivable heat.  To  show  this  property  of  steam 
by  experiment,  place  an  indefinite  amount  of 
water  in  a  closed  vessel,  and  let  a  pipe,  proceed- 


THE   LOCOMOTIVE   ENGINE.  13 

ing  from  its  upper  part,  communicate  with 
another  vessel,  which  should  be  open,  and,  for 
convenience  of  illustration,  shall  contain  just 
5J  Ibs.  of  water  at  32°,  or  just  freezing.  The 
pipe  from  the  closed  vessel  must  reach  nearly  to 
the  bottom  of  the  open  one.  By  boiling  the 
water  contained  in  the  first  vessel  until  steam 
enough  has  passed  through  the  pipe  to  raise  the 
water  in  the  open  vessel  to  the  boiling  point, 
(212°,)  we  shall  find  the  weight  of  the  water 
contained  by  the  latter  to  be  6J  Ibs.  Now  thia 
addition  of  one  pound  to  its  weight  has  resulted 
solely  from  the  admission  of  steam  to  it ;  and 
this  pound  of  steam,  therefore,  retaining  its  own 
temperature  of  212°,  has  raised  5J  Ibs.  of  water 
180°,  or  an  equivalent  to  990° ;  and  including 
its  own  temperature,  we  have  1202°,  which  it 
must  have  possessed  at  first. 

The  sum  of  the  latent  and  sensible  heat  of 
steam  is  in  all  cases  nearly  constant,  and  does 
not  vary  much  from  1200°.  It  is  from  this 
property  of  steam  that  it  becomes  of  such  essen- 
tial service  in  heating  buildings ;  one  square 
foot  of  superficial  surface  of  cast-iron  steam 
pipe  will  keep  200  cubic  feet  of  air  at  a  con- 


14  THE    LOCOMOTIVE   ENGINE. 

genial  summer  heat;  but  a  square  foot  of  the 
surface  of  a  bar  of  iron,  of  the  same  perceivable 
temperature,  would  scarcely  start  the  frost  on 
the  windows  in  a  cold  morning. 

If  a  known  volume  of  steam  of  a  certain 
pressure  be  made  to  occupy  but  one-half  that 
volume,  its  elastic  force  will  be  doubled  ;  or,  in 
other  words,  the  same  pressure  is  exerted  within 
one-half  the  original  capacity.  By  pressure  we 
mean  the  initial  elastic  force  of  the  steam,  which 
is  always  the  same  in  equal  weights  of  steam, 
and  which  can  only  act  with  greater  intensity 
of  pressure  by  restricting  the  area  exposed  to  its 
action.  In  fact,  it  is  an  established  law  of  steam, 
and  of  all  elastic  fluids  generally,  that  the  press- 
ure which  they  exert  is  inversely  as  the  space 
occupied;  or,  to  be  more  precise,  it  is  very 
nearly  so.  At  the  end  of  the  present  section  we 
shall  give  a  table  of  the  temperature  and  elastic 
force  of  steam,  which  will  show  the  exact  in- 
crease of  pressure  corresponding  with  any  dimi- 
nution in  bulk. 

The  elasticity  of  steam  increases  with  an  in- 
crease in  the  temperature  applied,  but  not  in  the 
same  ratio.  If  steam  is  generating  from  water 


THE   LOCOMOTIVE   ENGINE.  15 

at  a  temperature  winch  gives  it  the  same  pressure 
as  the  atmosphere,  an  additional  temperature  of 
38°  will  give  it  the  pressure  of  two  atmospheres ; 
a  still  further  addition  of  42°  gives  it  the  tension 
of  four  atmospheres ;  and  with  each  successive 
addition  of  temperature,  of  between  40°  and  50°, 
the  pressure  becomes  doubled.  It  is  well  for  the 
student  of  the  steam  engine  to  know  the  reason 
of  this  effect,  and  we  will  endeavour  to  explain  it. 
We  have  already  said  that  there  is  no  cohesion 
among  the  particles  of  fluids,  but  there  is,  how- 
ever, an  attraction  between  all  matter  in  nature. 
The  action  of  heat  in  generating  steam  has  to 
overcome  this  attraction  among  the  particles  of 
the  water,  and  likewise  the  gravity  of  the  water 
itself.  As  the  water  becomes  rarefied  by  heat, 
and,  either  in  its  natural  state  or  as  steam,  occu- 
pies a  greater  volume,  this  attraction  is  di- 
minished, and  also  the  weight  or  gravity  of  the 
water  ;  hence  an  additional  rate  of  temperature 
does  not  have  to  contend  with  the  same  resistance 
as  the  temperature  which  preceded  it,  and  is, 
therefore,  enabled  to  produce  greater  effects  in 
the  generation  of  steam. 

Among  a  variety  of  facts  and   notes  relative 


16  THE    LOCOMOTIVE    ENGINE. 

to  the  nature  of  steam,  we  select  the  follow- 
ing :— 

If  water  be  boiled  in  an  open  vessel,  no  tem- 
perature greater  than  that  for  the  boiling  point 
(which  for  fresh  water  is  212°)  can  be  produced 
in  it.  All  the  surplus  heat  which  may  be  applied 
passes  off  in  the  steam. 

If  the  vessel  be  closed,  and  the  steam  as  it  is 
formed  be  retained  within  it,  the  temperature 
may  be  raised,  and  retained  in  the  steam. 

If  the  steam,  as  it  is  formed,  is  allowed  to 
accumulate  in  the  boiler,  its  pressure  on  the 
water-level  makes  an  increased  temperature  ne- 
cessary to  continue  its  production. 

Steam,  in  itself,  is  invisible,  and  becomes 
visible  only  upon  condensation,  as  when  a  jet  is 
discharged  into  the  open  air ;  its  loss  of  tem- 
perature causes  it  to  condense,  and  we  see  it  in 
the  form  of  a  vapory  cloud. 

In  treating  of  steam,  the  term  heat  is  un- 
derstood as  expressing  its  sensible  heat,  while 
the  term  caloric  provides  for  the  expression  of 
every  conceivable  existence  of  temperature. 

To  explain  the  theory  of  ebullition,  or  boiling 
liquids,  we  will  observe  that  in  metals,  heat  is 


THE  LOCOMOTIVE   ENGINE.  17 

communicated  by  the  conducting  property  they 
possess ;  but  in  liquids  it  is  communicated  by  a 
circulation  of  particles.  If  heat  be  applied  to 
the  bottom  and  sides  of  a  vessel  containing 
water,  that  portion  of  the  water  in  contact  with 
the  heated  metal  becomes  heated  and  rarefied, 
and  consequently  lighter  than  the  rest,  whereby 
it  ascends  to  the  surface,  gives  off  its  vapour, 
becomes  cooled,  and  in  consequence  becoming 
heavier,  descends,  again  to  become  heated,  rise, 
and  descend  as  before,  and  to  maintain  these 
operations  in  a  constant  succession  so  long  as 
the  heat  is  applied.  This  action  is  performed  in 
vertical  planes,  and  if  the  heat  be  applied  above 
the  bottom  of  the  vessel,  the  water  below  that 
point  will  receive  but  little  heat,  and  can  never 
be  made  to  boil. 

An  established  relation  must  exist  between  the 
temperature  and  elasticity  of  steam ;  in  other 
words,  water  at  212°  must  be  under  the  pressure 
of  the  steam  naturally  resulting  from  that  tem- 
perature, and  so  at  any  other  temperature. 

If  this  natural  pressure  on  the  surface  of  the 
water  be  removed  without  a  corresponding  reduc- 
tion in  the  temperature,  a  violent  ebullition  at 
2* 


18  THE   LOCOMOTIVE    ENGINE. 

the  water-level  is  the  immediate  result.  Thus, 
suppose  the  entire  steam-room  in  a  boiler  to  be 
six  cubic  feet,  and  the  contents  of  the  cylinder 
which  it  supplies  to  be  two  cubic  feet;  at  each 
stroke  of  the  piston  one-third  of  all  the  steam  in 
the  boiler  is  discharged,  and  the  surface  of  the 
water  is  consequently  relieved  from  one-third  of 
the  pressure  upon  it  before  that  stroke.  The 
temperature  remains  the  same,  but  as  it  does  not 
bear  the  natural  relation  to  this  diminished  press- 
ure, it  causes  the  water  to  boil  violently,  and 
produces  foaming.  Foaming  is  a  cause  of  which 
priming  (or  working  water  along  with  the  steam 
into  the  cylinders)  is  the  effect.  Provision  must 
therefore  be  made  in  all  boilers,  that  they  may 
have  a  large  extent  of  steam-room  compared 
with  the  cylinders  which  they  supply. 

Another  result  attending  the  formation  of  steam 
is,  that  when  an  engine  is  in  operation  and  work- 
ing off  a  proper  supply  of  steam,  the  water-level 
in  the  boiler  artificially  rises,  and  shows  by  the. 
gauge-cocks  a  supply  greater  than  that  which 
really  exists.  This  is  owing  to  the  steam  forming 
in  the  water  and  rising  in  bubbles  to  the  surface, 
and  displacing  by  its  bulk  the  amount  of  water 


THE   LOCOMOTIVE   ENGINE.  19 

indicated  by  the  rise  at  the  gauge-cocks.  As  the 
production  of  steam  under  the  same  temperature 
cannot  continue  under  an  increased  pressure,  it 
follows  that  when  the  discharge  of  steam  is  stop- 
ped, and  its  entire  pressure  is  thrown  on  the  sur- 
face of  the  water,  steam  is  no  longer  generated, 
and  the  water  takes  its  natural  level. 

At  whatever  point  in  a  boiler  steam  be  taken, 
there  is  a  determination  of  water  to  that  point, 
which  is  occasioned  by  the  sudden  reduction  in 
the  pressure,  owing  to  the  withdrawal  of  the  steam. 
This  is  the  case  with  all  boilers  having  steam- 
domes  with  throttles  in  the  same ;  and  it  was  for 
this  reason  that,  on  a  new  engine  lately  constructed 
at  the  Eastern  Railroad  Shop,  at  East  Boston,  the 
steam-dome  was  omitted,  and  in  its  stead  a  steam- 
pipe,  perforated  on  its  upper  side,  was  extended 
the  whole  length  of  the  boiler,  occupying  the  po- 
sition usually  given  to  the  steam-pipe  in  ordinary 
locomotives.  The  object  of  this  was  to  take  the 
steam  alike  from  all  parts  of  the  steam-room  of 
the  boiler,  so  that  no  rise  of  witter  should  result 
at  any  one  point. 


iO  THE    LOCOMOTIVE   ENGINE. 


Notes. — One  cubic  foot  of  atmospheric  air  weighs  527-04 
Troy  grains,  while  an  equal  bulk  of  steam  at  212°  weighs 
258-3  grains,  the  specific  gravity,  therefore,  of  steam  at  the 
pressure  of  the  atmosphere,  and  taking  that  of  the  atmo- 
sphere at  1,  is  -490. 

The  force  of  steam  is  the  same  at  the  boiling  point  of  every 
fluid. 

27-104  cubic  feet  of  steam  at  the  pressure  of  the  atmo- 
sphere, equal  1  Ib.  avoirdupois. 

TABLE  OF  THE  TEMPERATURE  AND  ELASTIC  FORCE  OF  STEAM  : 
ALSO  THE  VOLUME  OF  STEAM  GENERATED,  COMPARED  WITH 
THE  QUANTITY  OF  WATER  FROM  WHICH  IT  IS  RAISED  AT 
DIFFERENT  PRESSURES. 

[Note. — Steam,  raised  from  water  at  212°,  has  no  pressure 
above  that  of  the  atmosphere,  and  can  produce  no  useiu.1 
effect  except  in  obtaining  a  vacuum  in  a  condensing  engine. 
If  admitted  to  one  end  of  a  cylinder,  it  would  expel  the  air, 
and  would  there  remain  without  producing  any  motion,  un- 
less the  pressure  of  the  atmosphere  on  the  back  of  the  piston 
was  removed.  In  this  table  we  have  therefore  given  the 
temperature  corresponding  with  the  steam  at  pressures  above 
that  of  the  atmosphere.  We  would  also  here  remark  that 
the  pressure  in  a  locomotive  or  other  boiler,  as  indicated  by 
the  safety-valve,  is  the  real  pressure  above  the  atmosphere, 
as  the  air  presses  upon  the  top  of  the  valve  with  the  same 
force  as  a  corresponding  pressure  of  steam  within.  In  a 
boiler  showing  50  Ibs.  pressure  per  square  inch,  by  the  safety- 
valve,  there  is  a  pressure  of  65  Ibs., — 15  Ibs.  of  which  are 
expended  in  overcoming  the  pressure  of  the  air  on  the  top  of 
the  valve.  Therefore,  the  remaining  50  Ibs.,  indicated  by 


THE    LOCOMOTIVE    ENGINE. 


21 


the  valve,  is  the  eiFective  pressure  for  a  non-condensing  en- 
gine, although  a  condensing  engine  would  realize  nearly  the 
full  effect  of  65  Ibs.] 


Pressure  in  Ibs.  abm 
the  atmosphere,  and  a 
BO  including  the  saiu 

30  Ibs.  45  Ibs. 
40    "    55    " 
50    «     65    " 
60    "     75    " 
70    "    85    « 
80    "    95    " 
90    "  105    " 
100    "  115    " 
110    "  125    " 
120    "  135    " 
130    "  145    « 
HO    "  155    " 

•e                 Temperature        Volume  of  steam  compare.1 
,1-                        in  deg.              with   that  of    the   watf: 
e.                  Fahrenheit.          from  which  it    is  raise. 

276-4  -  610 

289-3 

508 

301-3 

437 

311-2 
320-1 

383 
342 

328-2 

310 

335-5 

282 

342-5 
.    .  ..  349-0 

260 
241 

355-1 

;  225 

j  360-7 
1.  ......  366-2 

211 

..  198 

*. 

.-. 


SECTION  II. 

A   GENERAL    DESCRIPTION    OF    THE    CONSTRUCTION 
OF   THE   LOCOMOTIVE   ENGINE. 

HAVING  illustrated  the  prominent  properties  of 
steam,  it  remains  to  show  in  what  manner  its  use- 
ful effect  may  be  realized  in  the  production  of 
power  for  locomotive  purposes.  Any  reader 
would  be  aware  that  a  locomotive  must  combine 
within  itself  the  means  for  the  generation  of 
steam,  its  application  to  produce  motion  within 
the  machine  itself,  and  also  the  propulsion  of  the 
whole  upon  the  road.  A  complete  locomotive 
steam  engine,  therefore,  combines  three  distinct 
arrangements  for  realizing  these  conditions.  The 
source  of  power  lies  in  the  boiler  and  fire-box; 
the  cylinders,  valves,  piston,  and  the  connections 
are  the  means  by  which  it,  is  applied  to  produce 
motion  within  the  machine;  and  the  wheels,  by 
their  tractive  force  or  adhesion  to  the  rails,  secure 
the  locomotion  of  the  machinery  which  impels 

them,  and  also,  from  their  surplus  power  above 
20 


THE   LOCOMOTIVE   ENGINE.  25 

what  is  necessary  to  move  the  engine  alone,  the 
draught  of  a  great  load  upon  the  rails.  It  is 
therefore  necessary  to  understand  the  construc- 
tion of  each  of  these  parts,  and  also  the  general 
arrangement  by  which  they  are  combined  in  the 
production  of  power. 

A  reference  to  the  figure  on  the  opposite  page 
will  serve  to  show  the  construction  of  an  ordinary 
eight-wheeled  engine,  as  divided  in  the  direction 
of  the  length  of  the  boiler,  so  as  to  show  the  en- 
tire machinery  for  generating  and  applying  the 
power. 

The  boiler  A  in  which  the  steam  is  first  pro- 
duced, is  of  a  cylindrical  form,  having  a  furnace 
or  fire-box  B  at  one  end,  surrounded  by  a  water 
casing  a  a  communicating  with  the  boiler,  and 
which  is  to 'prevent  the  destruction  of  the  plates 
of  which  the  fire-box  is  formed  by  the  intense 
heat  of  the  fire.  The  plates  which  form  the  out- 
side of  this  water  casing  are  united  to  the  cylin- 
drical part  of  the  boiler,  and  form  what  is  called 
the  outside  fire-box.  This  outside  fire-box  sup- 
ports the  furnace  or  fire-box  proper  by  a  number 
of  stay  bolts,  seen  at  b,  b',  these  bolts  being 
screwed  at  their  ends  into  the  sides  of  both  fire- 

3 


26  THE   LOCOMOTIVE   ENGINE. 

boxes.  C  is  the  grate,  the  bottom  of  the  fire-box 
being  open  to  admit  the  air  necessary  for  the 
combustion  of  the  fuel,  and  D  is  the  door  through 
which  the  fuel  is  admitted.  At  c  e  are  shown  a 
number  of  small  copper  tubes,  their  purpose  being 
to  convey  the  heated  air  through  the  boiler,  from 
the  fire-box  to  the  smoke-box  E.  The  arrange- 
ment of  these  tubes  may  be  better  understood  by 
an  inspection  of  fig.  2,  which  shows  the  fire-box 
and  boiler  divided  transversely  across  its  diame- 
ter. They  are  very  small,  and  are  placed  so  as 
to  be  but  f  of  an  inch  apart  in  any  direction. 
They  are  also  very  thin,  so  as  to  communicate 
the-  heat  passing  through  them  to  the  water  which 
surrounds  them,  and  which  generally  stands  four 
or  five  inches  above  their  upper  or  top  row.  It 
is  the  surface  of  the  fire-box  and  the  exterior  sur- 
faces of  these  tubes  that  constitute  the  heating 
surface  of  the  boiler.  That  portion  of  the  boiler 
above  the  water-level  (which  is  shown  by  the 
dotted  line)  is  the  steam-room  of  the  boiler,  and 
is  occupied  by  the  steam  generated  from  the 
water  above  and  among  the  tubes  and  in  the 
water  space  around  the  fire-box.  The  forward 
compartment  of  the  boiler,  or^  smoke-box,  at  E, 


THE    LOCOMOTIVE    ENGINE.  27 

receives  the  surplus  of  heated  air  not  communi- 
cated to  the  water,  and  the  gaseous  products 
of  the  combustion  of  the  fuel  in  the  fire-box; 
and  the  chimney  F  provides  for  their  escape 
into  the  open  air.  The  draught  of  the  fire 


Fig.  2. 

through  the  tubes  is  excited  artificially  b^  the 
escape  of  the  steam  from  the  cylinders  of  the  en- 
gine, the  arrangement  and  operation  of  which  we 
shall  explain  hereafter.  This,  then,  is  the  ar- 
rangement by  which  the  power  applied  to  pro- 
duce locomotion  is  first  generated.  The  peculiar 


28  THE   LOCOMOTIVE    ENGINE. 

form  given  to  the  boiler,  the  contact  of  water 
with  the  sides  and  top  of  the  fire-box,  and  the 
great  extent  of  heating  surface  afforded  by  the 
disposition  of  the  tubes,  secure  the  rapid  produc- 
tion of  a  vast  volume  of  steam  within  very  re- 
stricted limits.  In  future  pages  we  shall  explain 
numerous  details  and  appendages  belonging  to 
the  boiler,  and  shall  give  its  best  proportions,  as, 
likewise,  of  every  other  part  connected  with  the 
engine. 

The  second  division  of  the  entire  arrangement 
of  the  engine  is  that  in  which  the  power  already 
generated  is  applied  to  produce  motion  within 
the  machine.  Upon  the  top  of  the  boiler  a 
cylindrical  chamber  or  dome  G  is  formed,  and 
the  pipe  which  conveys  the  steam  from  the 
boiler  penetrates  it  as  seen  at  H.  The  object 
of  elevating  the  mouth  of  the  steam  feed-pipe  is 
to  prevent  the  motion  of  the  engine  from  throw- 
ing particles  of  water  into  it,  to  be  carried  into 
the  cylinders  and  to  oppose  a  load  to  the  motion 
of  the  engine.  The  mouth  of  this  pipe  is  covered 
by  a  valve,  provided  with  ports  or  openings  to 
admit  steam  within  it,  and  the  admission  of 
Btearn  is  governed  by  the  motion  communicated 


THE   LOCOMOTIVE   ENGINE.  29 

to  the  valve  through  its  lever  g,  rod  A,  and 
starting  lever  i,  without  the  boiler  and  accessible 
from  the  footboard,  where  the  engineer  or  driver 
stands.  In  the  figure  this  valve  is  represented 
open,  and  the  steam  is  descending  through  the 
pipe,  in  which  it  passes  along  through  the  parti- 
tion between  the  boiler  and  smoke-box  and  down 
through  the  branch-pipe  I  into  the  steam-chest  J. 
This  steam-chest  communicates  with  each  end  of 
the  cylinder  M,  by  the  passages  seen  in  the 
figure,  and  steam  is  admitted  through  these  pas- 
sages* alternately  to  each  end  of  the  cylinder 
by  a  sliding  valve,  seen  at  K.  Within  the  cylin- 
der is  a  piston  L,  against  which  the  pressure  of 
the  steam  is  exerted  to  produce  motion.  In  the 
position  given  to  the  valve  K  in  the  figure,  the 
left-hand  passage  is  open  and  is  admitting  steam 
to  that  end  of  the  cylinder,  to  press  the  piston 
in  the  direction  of  the  arrow.  There  is  also  a 
quantity  of  steam  on  the  right  hand  of  the 
piston,  which  was  employed  in  the  preceding 
stroke  to  force  the  piston  to  the  left  hand  of  the 
cylinder;  and  its  work  being  now  done,  it  is 


*  Described  as  induction  ports. 
3* 


30  THE   LOCOMOTIVE   ENGINE. 

escaping  through  the  right-hand  passage,  and 
turning  in  a  cavity  in  the  under  side  of  the 
valve  into  a  third  passage  on  the  face  of  the 
cylinder,  and  which  is  situated  between  the  two 
induction  passages  already  mentioned.  The  ex- 
haust steam  is  carried  in  this  last  passage  a  short 
distance  around  the  cylinder,  and  passes  through 
an  opening  on  the  side  of  the  same,  into  the  bot- 
tom of  a  vertical  pipe,  part  of  which  is  seen  at  N. 
The  mouth  of  this  pipe  is  considerably  contracted, 
as  seen  in  the  figure,  and  the  resistance  given  by 
this  contraction  to  the  exit  of  the  steam  makes  it 
discharge  in  a  very  forcible  blast.  This  powerful 
draught  at  the  mouth  of  the  tubes  excites  the 
passage  of  the  heated  air  through  them,  and 
causes  a  great  intensity  in  the  fire.  Without 
this  artificial  draught  the  boiler  could  not,  from 
its  proportions  of  fire  surface,  generate  sufficient 
steam  to  supply  the  cylinders. 

We  have  seen  the  steam  entering  by  the  left- 
hand  passage  within  the  cylinder,  and  impelling 
the  piston  toward  the  opposite  end  of  the  same. 
As  the  piston  approaches  the  right-hand  ter- 
mination of  its  stroke,  the  valve  K  is  made  to 
shift  its  position  in  the  steam-chest,  and  to  close 


THE   LOCOMOTIVE   ENGINE.  31 

the  left-hand  passage,  and  likewise,  by  the  same 
motion,  to  open  the  opposite  or  right-hand  one. 
The  left-hand  passage  is  fully  closed  when  the 
piston  is  within  three  or  four  inches  of  the  end 
of  the  cylinder,  and  the  right-hand  passage 
almost  at  the  same  instant  begins  to  open,  so  that 
the  full  pressure  of  steam  is  exerted  against  the 
right-hand  side  of  the  piston  before  it  actually 
has  completed  its  stroke  in  that  ejection.  This 
advance  of  the  valve  on  the  piston  is  termed  the 
lead  of  the  valve,  and  when  confined  within  cer- 
tain limits  is  found  to  increase  the  speed  of  the 
engine,  as  it  allows  the  steam  to  act  with  a  con- 
cussive  force,  like  that  of  a  spring,  at  the  ends 
of  the  strokes,  so  as  to  lose  no  time  in  changing 
the  motion  of  the  piston.  When  the  piston  has 
commenced  on  its  return  stroke,  and  while  it  is  in 
its  motion,  the  valve  moves  likewise  in  the  same 
direction,  uncovering  the  right-hand  passage 
more  and  more,  until,  when  the  piston  has 
returned  to  the  position  shown  in  the  figure,  or  to 
the  middle  of  the  stroke,  this  passage  is  fully 
open  ;  the  same  as  the  left-hand  passage  shown 
in  the  figure  to  admit  steam  for  the  preceding 
stroke. 


8J  THE   LOCOMOTIVE   ENGINE. 

^he  motion  of  the  valve  has  transferred  the 
cavity  on  its  under  side  to  the  left-hand  pas- 
sage, and  the  steam,  which  during  the  preceding 
stroke  was  admitted  through  that  passage,  will 
now  discharge  through  it,  and  pass  into  the  ex- 
baust  port  and  up  the  exhaust  pipe  N,  as  already 
described.  By  the  time  the  piston  has  reached 
the  middle  of  its  stroke  the  valve  will  have 
reached  the  end  of  its  motion  on  the  face  of  the 
cylinder,  and  will  begin  to  move  the  contrary 
way,  so  that  during  the  last  half  of  the  stroke 
of  the  piston,  the  piston  and  valve  move  in  oppo- 
site directions. 

The  cavity  on  the  under  side  of  the  valve,  in 
which  the  steam  turns  from  the  induction  into  the 
eduction  port,  must  receive  such  a  width  of  open- 
ing as  to  allow  the  exhaust  steam  to  commence  its 
escape  from  one  end  of  the  cylinder  before  steam 
is  admitted  to  the  opposite  end;  so  that  if,  for 
instance,  the  lead  of  the  valve  on  the  induction 
side  be  J  of  an  inch,  the  exhaust  must  have  a 
lead  of  about  J  inch.  In  other  words,  when  one 
steam  port  is  taking  steam  through  J  of  an  inch 
the  other  port  must  be  discharging  steam  through 
J  of  an  inch.  This  is  necessary  for  the  free 


THE   LOCOMOTIVE    ENGINE. 

escape  of  the  steam,  that  it  may  oppose  no  load 
to  the  progress  of  the  engines. 

We  are  now  to  show  how  the  motion  of  the 
piston  is  communicated  to  the  wheels,  and  in 
what  manner  the  sliding  valve  K  is  moved  within 
the  steam-chest,  so  as  to  regulate  the  admission 
of  steam  to  the  cylinder ;  and  to  guard  against 
any  misconception  on  the  part  of  the  reader,  we 
will  say  here  that  there  are  two  steam-chests  and 
two  valves  and  cylinders,  together  with  two  entire 
but  similar  arrangements  for  communicating  the 
power  exerted  against  the  pistons  to  the  wheels. 
The  figure  will  admit  of  the  representation  of 
but  one  engine,  (the  cylinder  and  its  valve  and 
piston  being  the  engine,)  the  other  being  behind 
the  one  we  have  shown.  The  steam-pipe  H,  after 
passing  through  the  partition  between  the  boiler 
and  smoke-box,  is  divided  into  two  smaller  pipes, 
one  of  which  conveys  the  steam  to  each  cylinder. 

Within  the  centre  of  the  body  of  the  piston  is 
keyed  the  rod  P,  which  passes  through  a  stuffing 
box  in  the  cover  of  the  cylinder,  and  is  attached 
at  its  other  end  to  a  cross-head  having  a  pin  or 
bearing  for  a  connecting  rod.  This  cross-head  is 
also  attached  to  guides,  to  insure  the  motion  of 


84  THE    LOCOMOTIVE    ENGINE. 

the  piston-rod  in  the  line  of  the  axis  of  the  cylin- 
der. The  connecting  rod  r  takes  hold  of  this  pin 
at  one  end,  and  at  the  other  to  a  wrist  or  bearing 
of  the  crank  axle  a,  upon  the  extremities  of  which 
axle  are  keyed  the  driving  wheels  of  the  engine. 
As  there  are  two  cylinders  and  connecting  rods, 
there  are  necessarily  two  cranks  in  this  axle,  and 
they  are  placed  at  right  angles  one  with  the  other, 
so  that  one  piston  may  be  exerting  its  entire  force 
against  it,  while  the  other  is  changing  the  direc- 
tion of  its  motion,  and  is  exerting  but  compara- 
tively little  power. 

The  alternate  motion  of  the  pistons  is  thus  con- 
verted into  a  continuous  circular  motion,  and  it  is 
from  this  motion  that  the  movement  for  operating 
the  valves  is  derived  in  the  following  manner: — 
Four  eccentric  pulleys,  the  action  of  which  is  the 
same  as  that  of  short  cranks,  are  affixed  to  the 
axle  between  the  two  cranks.  There  are  two 
eccentrics  for  each  cylinder,  one  being  set  at 
such  an  angle  with  the  crank  for  that  cylinder  as 
to  give  the  proper  motion  to  the  valve  for  a  for- 
ward motion  of  the  engine,  and  the  other  to  pro- 
duce a  backward  or  retrograde  motion.  These 
eccentrics  are  encircled  each  with  a  brass  strap, 


THE   LOCOMOTIVE   ENGINE.  85 

to  which  is  attached  a  rod  t,  having  a  hook  at  its 
remote  end.  At  u  is  a  rocker  shaft  provided  with, 
arms  on  its  upper  and  lower  sides.  If  the  hook 
of  the  forward  eccentric  rod  be  dropped  on  a  pin 
in  the  lower  arm,  the  motion  of  the  forward  ec- 
centric will  he  communicated  to  the  valve  through 
the  rocker  shaft  'u  and  its  upper  arm,  and  the 
valve  stem  v.  And  so  of  the  hook  in  the  hack- 
ward  eccentric  rod.  Another  shaft  mounted  with 
arms  or  cams,  and  governed  by  a  lever  within 
reach  of  the  engineer,  is  made  to  throw  out  either 
the  forward  or  backward  or  all  the  hooks  in  the 
.eccentric  rods.  This  shaft  is  laid  immediately 
beneath  the  hooks,  and  traverses  in  the  same 
direction  as  the  rocker  shaft  u. 

It  will  now  be  easy  to  trace  the  operation  of 
the  steam,  and  of  the  machinery  put  in  motion  by 
its  action  on  the  piston.  The  throttle  valve  at 
die  mouth  of  the  steam-pipe  H  being  open  by  the 
lever  i,  the  steam  will  be  admitted  to  within  the 
pipe,  and  will  descend  through  it  and  through  the 
branch-pipe  I  into  the  steam-chest  J.  From  here 
it  will  find  its  way  into  the  cylinder  through 
whichever  passage  that  may  be  open ;  and  as  that 
is  here  the  left-hand  one  it  will  be  admitted  to 


36  THE   LOCOMOTIVE   ENGINE. 

press  against  the  left-hand  side  of  the  piston, 
and  to  move  it  toward  the  opposite  end  of  the 
cylinder,  by  which  time  the  right-hand  passage 
will  have  been  open  to  admit  steam  to  force 
the  piston  back  again.  The  motion  of  the  piston 
will  be  communicated  to  the  axle  of  the  driving 
wheels,  through  the  piston  rod  p,  connecting 
rod  r,  and  crank  s ;  and  the  motion  so  trans- 
mitted will  cause  the  eccentrics  to  turn,  and 
by  their  motion  to  operate  the  valve  through 
the  eccentric  rod  £,  rocker  shaft  and  arms  u, 
and  valve  stem  v9  so  as  to  maintain  the  ad- 
mission of  steam  to  the  cylinder  in  the  manner 
described.  The  driving  wheels  as  they  are 
turned  will,  by  their  adhesion  to  the  rails,  move 
along  the  engine  and  its  load ;  and  the  constant 
recurrence  of  these  motions  in  the  piston,  valve, 
and  their  subordinate  connections,  will  maintain 
the  action  necessary  to  produce  this  required 
progressive  motion  of  the  machine. 

Of  the  remaining  parts  of  the  engine,  0  shows 
an  additional  pair  of  driving-wheels,  connected 
with  those  fixed  to  the  crank  axle,  and  turning 
with  them.  The  object  of  this  second  pair  of 
wheels  is  to  obtain  a  greater  adhesion  to  the  rails 


THE    LOCOMOTIVE    ENGINE.  37 

than  with  only  one  pair,  and  also  to  relieve  the 
principal  pair  of  drivers  from  the  great  weight 
of  the  engine,  which  would  otherwise  come  upon 
them — at  least,  all  that  portion  not  supported  by 
the  truck  wheels,  T.  The  drivers  on  the  crank 
axle  generally  have  plain  rims,  while  those  on 
the  hind  axle  have  flanges  on  their  inner  sides,  as 
likewise  the  forward  or  truck  wheels,  in  order  to 
keep  the  engine  on  the  rails.  The  four  forward 
wheels  are  combined  in  a  separate  frame  which 
turns  around  a  pintal  secured  to  the  body  of  the 
engine,  and  is  to  facilitate  the  passage  of  the 
engine  around  curves.  There  are  springs  over 
the  bearings  of  the  wheels  to  relieve  the  engine 
from  shocks  arising  from  inequalities  passed  over 
on  the  rails.  There  are  pumps,  which  are  not 
shown  in  the  figure,  for  supplying  the  boiler  with 
water,  as  it  is  evaporated  in  the  production  of 
steam.  These  are  of  the  forcing  kind  and  are 
attached  to  the  cross-head  or  to  a  pin  on  the 
outside  of  the  driving-wheels. 

The  boiler  is  provided  with  a  pair  of  safety 
valves  to  provide  for  the  escape  of  steam  when  it 
attains  an  unnecessary  pressure,  and  the  engine 
has  also  a  whistle  and  bell  for  alarms  and  signals. 


38  THE   LOCOMOTIVE   ENGINE. 

Many  recent  engines  have  expansion  or  cut-off 
valves,  the  use  of  which  we  shall  hereafter  ex- 
plain. 

From  what  we  have  said  we  believe  any  one 
may  acquaint  himself  with  the  general  arrange- 
ment and  operation  of  the  locomotive  engine. 
Our  remarks  on  future  pages  will  explain  various 
details  which  would  embarrass  the  reader  on  a 
first  introduction  to  the  machine,  but  which  will 
serve  to  extend  his  acquaintance  after  he  has 
mastered  the  leading  principles  of  its  action. 
The  principal  features  of  the  engine,  including 
the  construction  of  the  boiler  and  the  operation 
of  the  steam  in  the  cylinders,  are  universally  the 
same,  but  there  are  various  modifications  in  the 
arrangement  of  the  subsidiary  machinery,  which 
distinguish  the  engines  of  different  builders,  with- 
out affecting,  however,  the  purposes  for  which 
they  are  employed. 


SECTION  III. 

DETAILS    OF    THE    LOCOMOTIVE    ENGINE. —  THE 
BOILER   AND   ITS   APPENDAGES. 

THERE  are  several  essential  requisites  which 
locomotive  boilers  must  possess,  among  which  are 
strength,  lightness,  and  efficient  qualities  for  the 
production  of  steam;  and  these  requisites  can 
only  be  obtained  by  giving  very  particular  atten- 
tion to  the  material  of  which  a  boiler  is  made, 
and  of  the  manner  in  which  it  is  manufactured. 

Owing  to  the  diminished  strength  of  large  boil- 
ers compared  with  small  ones,  the  diameter  is 
very  rarely  made  greater  than  4  feet  outside  of 
the  iron.  The  plates  of  which  the  cylindrical 
part  of  the  boiler  and  the  fire-box  are  formed,  are 
from  T5g  inch  to  •§  inch  thick.  Lowmoor  iron  is 
generally  preferred ;  and  the  quality  of  the  iron 
is  determined  by  its  general  appearance  and  its 
established  reputation  among  builders  and  others. 
"VVe  have,  however,  much  American  iron  of  a  very 

excellent  quality,  which  comes  to  the  boiler-maker 

su 


40  THE   LOCOMOTIVE    ENGINE. 

entirely  warranted  by  responsible  dealers.  Angle 
iron  is  often  used  to  connect  the  cylindrical  part 
of  the  boiler  to  the  outside  fire-box,  and  to  the 
smoke-box.  The  selection  of  this  iron  requires 
some  skill  and  experience,  as  much  of  it  is  liable 
to  be  reedy  in  its  structure ;  and  for  this  reason 
some  builders  obtain  the  proper  flanges  for  joining 
the  boiler  to  the  fire  and  smoke-boxes  by  turning 
over  the  edge* of  the  boiler  plate  of  which  th«3 
shell  is  formed.  The  rivets  about  locomotive 
boilers  are  from  f  inch  to  f  inch  in  diameter,  and 
have  a  pitch  of  1J  inches,  more  or  less.  The 
stay-bolts  to  secure  the  inside  fire-box  are  for  the 
most  part  f  inch  in  diameter,  and  4  J  inches  apart. 
These  stay-bolts  are  tapped  into  the  inside  and 
outside  fire-boxes  and  are  then  riveted  at  each 
end.  Their  diameter  and  number  should  depend 
somewhat  on  the  width  of  the  water  space  around 
the  fire-box ;  for  if  this  be  pretty  wide,  they  must 
necessarily  be  long  in  proportion  to  their  diame- 
ter. The  usual  number  of  stay-rods  in  a  boiler  is 
6  or  7  for  a  40-inch  boiler,  and  a  greater  number 
as  the  diameter  of  the  boiler  is  increased.  These 
rods  are  |  inch  to  an  inch  in  diameter,  and  are 
tapped  through  the  back  sheet  or  sheet  next  to 


THE   LOCOMOTIVE   ENGINE.  41 

the  foot-board  of  the  fire-box,  and  through  the 
back  sheet  also  of  the  smoke-box,  and  then  have 
a  large  nut  screwed  tightly  up  at  the  smoke-box 
end,  (there  being  a  head  at  the  fire-box  end,) 
and  having  a  little  red-lead  putty  interposed  be- 
tween the  nut  and  the  boiler-plate  to  insure  a 
tight  joint.  Some  makers  employ  right  and  left 
nuts  in  these  rods,  to  draw  them  up  to  a  proper 
strain,  but  these  are  hardly  necessary.  The  bars 
to  stay  the  crown  of  the  fire-box  are  generally  5 
or  6  in  number,  and  are  2  inches  thick,  and  from 
2  J  to  3-  inches  deep.  These  bars  must  rest  upon 
the  top  of  the  fire-box  only  at  their  ends,  a  space 
of  J  to  f  inch  being  left  all  along  their  under 
edges,  to  prevent  the  crown  sheet  of  the  fire-box 
from  becoming  burirt  through,  owing  to  an  ab- 
sence of  water  at  those  points.  At  the  points, 
however,  where  they  are  riveted  to  the  crown 
sheet,  washers  or  thimbles  must  be  placed  in  this 
space  for  the  rivets  to  pass  through,  in  order  that 
they  may  have  a  bearing  and  not  spring  up  the 
crown  sheet. 

In  all  ordinary  boilers  where  wood  is  used  as 
fuel,  all  parts  of  the  boiler,  with  the  exception  of 
the  tube  plate  at  the  fire-box  end,  are  formed  of 

4* 


42  THE   LOCOMOTIVE    ENGINE. 

iron.  These  tube  plates,  by  many  makers,  are 
made  of  copper.  Hinkley's  tube  plates  are  f  incn 
thick.  In  Winans'  Coal  Engines,  however,  the 
fire-box  is  made  of  f  inch  copper,  and  the  tube 
sheet  of  J  inch  iron.  The  tubes  are  also  of 
wrought  iron. 

The  tubes  in  wood  engines  are  made  mostly  of 
No.  14  copper,  their  outside  diameter  being  usually 
If  inch.  Wrought  iron  thimbles  for  tubes  are 
used  by  most  builders,  generally  at  the  fire-box 
end,  but  in  some  cases  at  both  ends  of  the  tubes. 
We  could  point  to  some  engines  having  no  thimbles 
at  either  end  of  the  tubes,  and  which  show  as 
tight  joints  as  many  engines  having  thimbles. 
Much,  indeed,  depends  upon  the  management  of 
a  boiler.  If  an  engineman  is  in  the  habit  of  put- 
ting out  his  fire  by  throwing  two  or  three  buckets 
of  water  into  the  fire-box  on  every  slight  emer- 
gency, or  running  with  the  door  open  to  regulate 
the  fire,  the  contraction  produced  in  such  cases 
by  the  sudden  cooling  of  the  flue  sheets  often 
works  nearly  every  tube  loose. 

A  method  of  tightening  tubes  has  been  used 
by  the  Lowell  Machine  Shop,  which  has  given 
good  results.  It  is  to  take  a  short  piece,  say  2 


THE   LOCOMOTIVE   ENGINE.  43 

• 

incnes  in  length,  of  No.  14  copper  tube,  and  of 
such  diameter  as  to  allow  of  its  just  sliding  into 
the  mouth  of  the  boiler  tube ;  it  is  firmly  united 
to  the  latter  by  a  brazed  joint  an  inch  long. 
What  remains  of  the  short  tube  projecting  out  is 
passed  through  the  tube  sheet,  which  is  drilled  to 
receive  it,  and  the  portion  projecting  beyond  the 
tube  sheet  is  then  turned  over  and  headed  in  the 
usual  manner.  This  brings  the  end  of  the  boiler 
tube  up  to  a  tight  bearing  with  the  inside  of  the 
tube  sheet. 

With  long  copper  tubes  it  is  sometimes  deemed 
advisable  to  give  them  a  middle  bearing,  for 
which  purpose  a  sheet  is  placed  midway  of  their 
length  and  passing  up  high  enough  to  support  the 
top  row.  Our  opinion,  however,  is,  that  these 
intermediate  flue-sheets  intercept  the  circulation 
of  the  water,  and  in  some  cases  occasion  priming. 
We  have  observed  this  to  be  the  case  in  some 
of  Norris's  engines,  which,  having  tubes  10  ft. 
8  in.  long,  were  provided  with  these  extra  sup- 
ports. 

The  braces  which  support  the  boiler  and  serve 
to  connect  it  to  the  frame  are  made  either  round 
or  flat.  When  made  round,  they  are  made  about 


44  THE   LOCOMOTIVE    ENGINE. 

2J  inches  in  diameter,  and  are  turned,  which  adds 
much  to  their  appearance. 

The  angle-iron  which  secures  the  fire-box  to 
the  frame  should  extend  the  whole  length  of  the 
fire-box,  if  there  is  nothing  in  the  way  to  prevent 
it.  It  should  be  screwed  tightly  to  the  frame, 
and  the  screws  to  fasten  it  to  the  fire-box  should 
pass  through  the  water  space,  being  tapped 
through  both  sheets.  The  heads  of  these  screws 
should  project  outward  considerably,  as  they  are 
difficult  to  unscrew  when  it  becomes  necessary  to 
remove  them.  There  should  be  two  rows  of 
screws  passing  into  the  fire-box,  one  above  the 
other ;  and  the  distance  between  the  screws  should 
be  just  sufficient  to  enable  a  wrench  to  be  readily 
introduced  to  turn  them. 

The  grates  are  always  of  cast  iron,  and  are 
generally  4  inches  deep  at  the  centre.  Their 
thickness  is  about  f  of  an  inch  on  their  upper 
edge,  and  f  inch  at  the  bottom.  The  space  be- 
tween them  is  f  inch.  We  know  of  one  or  two 
engines  which  were  found  to  make  steam  much 
better  by  placing  a  piece  of  plate  iron,  six  or 
eight  inches  wide,  across  the  fire-box  at  that  end 
of  the  grates  next  the  tube  sheet.  By  admitting 


THE    LOCOMOTIVE    ENGINE.  45 

air  through  the  whole  extent  of  grate  surface,  a 
large  quantity,  of  cold  air  naturally  passes  up 
close  to  the  side  of  the  fire-box,  below  the  tubes, 
the  draft  being  strongest  there,  and,  from  not 
passing  directly  through  the  fire,  escapes  into  the 
tubes  before  it  is  properly  heated.  As  this  cools 
the  tubes,  it  consequently  checks  the  formation 
of  steam ;  therefore,  by  not  admitting  the  air  be- 
neath the  ends  of  the  tubes,  but  causing  all  the 
air  to  pass  directly  through  the  fire,  it  was  found 
that  more  steam  could  be  produced  with  the  same 
fuel. 

The  grate  should  be  a  very  few  inches  above 
the  bottom  of  the  water  space  around  the  fire-box, 
in  order  that  the  water  below  it  may  remain  qui- 
escent and  collect  any  sediment  that  may  deposit 
itself  there. 

The  junction  of  the  inner  and  outer  fire-box  at 
the  bottom  of  the  water  space  is  made  with  a  bar 
of  wrought  iron  1J  inches  thick,  having  rivets 
passed  through  it  and  headed  on  the  outside  of 
the  fire-box  sheets.  Some,  however,  bend  the 
sheet  of  the  inner  fire-box  outward,  until  it  meets 
that  of  the  outer  fire-box,  and  then  rivet  them 
together.  This  method,  though  cheaper,  does  not 


46  THE   LOCOMOTIVE    ENGINE. 

allow  the  water  spaces  to  be  so  readily  cleared  of 
mud  and  deposite. 

Norris  and  some  other  southern  builders  con- 
struct their  boilers  with  the  top  of  the  fire-box 
worked  into  a  hemispherical  form,  and  having  a 
small  cast  iron  dome  placed  upon  the  top.  This 
makes  a  very  high  dome,  and  gives  a  large  amount 
of  steam  room ;  but  this  form  of  fire-box  has  seve- 
ral disadvantages,  among  which  is  the  extra  ex- 
pense of  a  boiler  constructed  in  this  way,  there 
being  work  about  the  fire-box  which  can  be  done 
only  by  very  skilful  workmen,  and  requiring  much 
more  riveting.  Again;  the  height  of  the  dome 
is  liable  to  make  the  engine  top-heavy,  which,  in 
engines  having  large  wheels,  and  having  the  boiler 
set  pretty  well  up,  is  quite  a  serious  objection. 
The  dome,  also,  from  exposing  so  large  an  extent 
of  heated  surface,  makes  the  interior  of  the 
"cab,"  over  the  footboard,  insufferably  hot,  which 
is  by  no  means  a  trifling  matter  to  a  man  who 
has  to  stand  in  its  heat  for  several  hours  together. 
With  all  this  the  size  of  the  dome  obstructs  the 
lookout  of  the  engineman,  and  the  diagonal  brace 
necessary  to  steady  it  lies  directly  in  his  way. 
With  all  these  objections  against  it,  this  form  of 


THE   LOCOMOTIVE   ENGINE.  47 

dome  can  hardly  be  said  to  possess  any  advan- 
tages over  the  old-fashioned  wagon-top  fire-box, 
having  a  low  cylindrical  dome;  although  it  is 
generally  considered  that  drier  steam  can  be 
worked  from  a  "dome  boiler,"  as  these  boilers 
are  termed. 

Hinkley  forms  a  cylindrical  dome,  about  22 
inches  in  diameter  and  18  inches  in  height,  about 
midway  on  the  boiler  between  the  fire-box  and 
smoke-box.  This  dome  has  a  cast  iron  cover  of 
sufficient  thickness  to  withstand  the  pressure  of 
the  steam,  and  of  such  size  that  the  aperture 
which  it  closes  may  admit  a  man  to  the  interior 
of  the  boiler.  The  steam-pipe  and  throttle  are 
placed  on  one  side  of  the  dome,  so  as  not  to 
obstruct  the  passage.  The  dome  is  made  of  the 
same  iron  as  the  shell  of  the  boiler,  is  lagged,  and 
covered  with  sheet  iron  in  the  same  manner,  and 
has  a  thin  cast  iron  base  and  cap. 

It  is  believed  by  many  that  a  point  near  the 
smoke-box  end  of  the  boiler  is  the  most  favourable 
place  from  which  to  take  the  steam,  as  it  is  con- 
sidered that  the  water  is  not  in  so  violent  a  state 
of  ebullition  at  that  point  as  at  the  fire-box  end. 

Locomotives  generally  have  two  safety-valves ; 


48  THE   LOCOMOTIVE   ENGINE. 

one  of  2J  inches  in  diameter,  next  the  footboard, 
and  one  of  3J  inches  diameter,  at  the  forward  end 
of  the  boiler.  We  see  no  reason  for  this  differ- 
ence of  size,  unless  the  safety-valve  next  the  foot- 
board cannot  have  a  lever  long  enough  for  a 
larger  valve  without  it  projects  out  in  the  way  of 
the  engineman.  The  lever  could  be  turned  to 
one  side,  and  thus  admit  the  use  of  a  larger 
valve.  Large  valves  of  3J  inches  or  4  inches  in 
diameter  are  less  liable  to  stick,  as  their  bearing 
surfaces  increase  only  directly  as  their  diameters, 
while  the  pressures  upon  them  increase  directly 
as  their  squares.  Thus  a  four-inch  valve  has  but 
twice  the  bearing  surface  or  circumference  of  a 
two-inch  valve,  while  the  pressure  on  it  would  be 
four  times  greater.  A  mitre  bevel,  which  is  the 
bevel  usually  given  to  the  safety-valves,  seems 
too  sharp.  Were  the  bevel  an  angle  of  about 
30°,  that  is  to  say  having  J  inch  depth  to  J  inch 
width  of  valve  seat,  there  would  be  no  difficulty 
with  the  valves  as  to  sticking. 

The  whistles  used  on  many  locomotives  are  of 
yery  heavy  tone,  and  are  6  inches  in  diameter. 
These  whistles  have  a  valve  stem  passing  down 
through  the  centre  and  operated  by  a  bent  lever 


THE   LOCOMOTIVE   ENGINE.  49 

outside.  The  exit  passage  of  the  steam  from  the 
lower  cup  should  be  about  35  inch  in  width,  while 
the  bottom  of  the  upper  cup  should  be  chamfered 
on  the  inside  so  as  to  bring  it  nearly  to  a  sharp 
edge.  This  sharp  edge  of  the  upper  cup  should 
be  placed  directly  over  the  annular  opening  in  the 
lower  cup,  that  the  steam  from  the  latter  may  im- 
pinge directly  upon  it.  A  whistle  4J  inches  in 
diameter,  and  of  the  composition  of  which  clock- 
bells  are  made,  gives  a  very  clear  and  sonorous 
sound.  The  upper  cup,  however,  is  most  com- 
monly made  of  sheet  brass  or  copper. 

The  spark  arresters  in  general  use  on  New 
England  locomotives  are  the  common  bonnet 
sparker,  the  patent  sparker  of  French  and  Baird 
of  Philadelphia,  and*  Cutting's  sparker.  The 
bonnet  sparker  is  the  most  common.  A  chimney 
of  sheet  iron,  about  4  feet  in  height,  is  placed 
over  the  opening  in  the  smoke-box,  and  a  curved 
cast  iron  disc  is  placed  immediately  over  this 
chimney.  The  cinders  and  sparks  projected  by 
the  blast  pipes  against  this  disc  receive  from  the 
form  given  to  it  a  change  in  their  motion,  which 
throws  them  down  between  the  bottom  of  the 

chimney  and   the   outer   casing   surrounding   it 
5 


50  THE    LOCOMOTIVE   ENGINE. 

j?he  smoke  and  steam  also  receive  this  motion, 
but  readily  rise,  and,  passing  around  the  disc, 
come  out  through  a  wire  netting  at  the  top. 
This  wire  netting  is  to  throw  down  such  sparks  as 
might  have  been  carried  with  the  steam  and 
would  otherwise  have  been  thrown  out  upon  the 
track,  becoming  a  source  of  danger  to  bridges 
and  buildings  along  the  line.  A  pipe  sometimes 
leads  from  the  bottom  of  the  outer  casing  of  the 
sparker  to  a  spark-box  on  the  front  or  sides  of 
the  smoke-box.  This  box,  we  believe,  is  termed 
the  "Sub-Treasury." 

French  and  Baird's  sparker  and  Cutting's 
sparker  are  not  in  so  general  use  as  the  bonnet 
sparker,  and  could  not  be  readily  understood 
without  the  aid  of  engravings  showing  their 
structure. 

The  opening  made  for  the  chimney  in  the  top 
of  the  smoke-box  is  about  the  same«size  as  the 
diameter  of  the  cylinder  of  the  engine.  The 
following  rule,  however,  will  be  found  to  apply 
in  all  wood  engines: — Divide  the  number  of 
square  inches  in  the  grate  by  7-5,  and  the  quo- 
tient expresses  the  area  of  the  chimney  in  square 
inches. 


THE   LOCOMOTIVE   ENGINE.  51 

Example. — What  should  be  the  diameter  of  a 
chimney  for  a  boiler  having  a  grate  34  inches  by 
35  inches  ? 

34 

35 

7-5)1190(158.6,  Area  of  chimney. 

And  by  calculation  we  find  the  nearest  cor- 
responding diameter  to  this  area  to  be  14J 
inches. 

The  ash  pan  of  a  boiler  is  a  plate  iron  tray, 
suspended  by  hooks  or  latches  to  the  bottom  of 
the  fire-box,  and  should  have  a  clear  depth  of  9 
inches — the  front  side  being  left  open  to  admit 
the  air  to  the  grates.  The  mouth  or  open  side 
of  the  ash  pan  should  be  provided  with  a  wire 
netting,  and  a  damper  of  plate  iron  turning  on  a 
hinge  should  be  fixed  to  draw  up  at  pleasure  by  a 
small  chain  passing  up  to  the  footboard. 

The  gauge-cocks  are  three  in  number,  and  are 
on  the  hind  sheet  of  the  fire-box,  within  reach  of 
the  engineman.  They  must  communicate  with 
the  boiler  at  such  a  point  that  should  the  water 
chance  to  fall  a  trifle  below  the  lower  cock  the 
upper  row  of  tubes  shall  not  be  uncovered.  In 


52  THE    LOCOMOTIVE    ENGINE. 

ascending  a  grade  of  80  feet  per  mile,  the  water 
at  the  fire-box  end  would  stand  two  inches  higher 
above  the  tubes  than  at  the  smoke-box  end ;  the 
gauge-cocks  should  therefore  communicate  with 
the  boiler  at  so  high  a  point  that  neither  end  of 
the  tubes  could  become  uncovered  under  any 
ordinary  circumstances  without  their  giving  warn- 
ing of  it. 

The  English  have  always  used  glass  gauge- 
tubes  in  addition  to  the  three  gauge-cocks,  but 
one  tried  on  an  engine  on  the  Maine  road  broke 
in  the  first  trial.  To  stand  the  action  of  the 
steam,  the  interior  of  the  tube  should  be  round, 
not  formed  like  a  thermometer  tube,  and  the  bore 
of  the  tube  should  not  exceed  T35  inch ;  the  glass 
should  be  thick  and  well  annealed,  and  there 
should  be  an  expansion  joint  at  the  upper  end 
of  it.  If  these  conditions  are  observed,  glass 
gauge-tubes  can  be  used  here  as  well  as  in 
England. 

The  blow-off  cocks  of  locomotives  should  be 
on  the  back  side  of  the  fire-box,  to  prevent 
the  steam  and  water  escaping  by  them  from 
blowing  up  sand  into  the  bearings  of  the  en- 
gine. 


THE   LOCOMOTIVE   ENGINE.  53 

The  mud-hole  plugs  are  of  brass,  and  are 
about  If  inches  in  diameter,  and  are  tapped  into 
the  outer  fire-box  at  the  bottom  of  the  water 
space.  They  should  have  stout  square  heads, 
as  it  is  very  difficult  to  turn  them  out  when  they 
have  been  a  short  time  in  use. 

Having  thus  explained  the  details  and  uses 
of  the  boiler  and  its  appendages,  we  will  pro- 
ceed to  give  the  proportions  adopted  by  different 
makers. 

The  table  of  dimensions  given  on  the  next 
page  includes  two  of  Hinkley's  patterns,  two 
of  the  Lowell  Machine  Shop  engines,  and  also 
of  Souther's  15  in.  cylinder  pattern. 


THE   LOCOMOTIVE   ENGINE. 


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THE   LOCOMOTIVE   ENGINE.  55 

The  15- inch  cylinder  machines  built  at  Taunton 
have  726  sq.  ft.  of  tube  surface,  11-23  sq.  ft.  of 
grate,  and  steam  ports  14  by  1  in.  The  per- 
formance of  these  engines  (with  blast  pipes  2f  in. 
at  the  mouth)  is  very  superior.  The  Taunton 
Company  give  the  largest  proportion  of  heating 
surface  to  a  given  capacity  of  cylinder  of  any 
of  the  engine  builders  in-  New  England. 

In  giving  the  fire-box  surface,  we  have  reck- 
oned every  inch  of  surface  above  the  grate, 
deducting  only  for  the  tubes  and  the  door.  It 
is  of  course  plain  that  all  this  surface  is  in  con- 
tact with  the  water  in  the  boiler,  although  it  is 
customary  among  engineers  not  to  include  any 
portion  of  that  side  of  the  fire-box  next  the 
tubes  as  heating  surface. 

It  will  be  seen  from  the  table  that  Hinkley's 
15-inch  cylinder  engine  ^has  the  greatest  extent 
of  heating  surface,  compared  with  its  capacity 
of  cylinder,  of  the  five  engines  given;  and  as 
the  proportions  adopted  appear  to  answer  very 
well,  we  will  give  the  multipliers  which  will 
give  the  same  proportions  for  any  other  size  of 
cylinder. 

Multiply   the  square  of  the  diameter  of  the 


56  THE   LOCOMOTIVE   ENGINE. 

cylinder  by  3*159,  to  get  the  Heating  surface 
of  the  tubes ;  by  -252,  to  get  the  heating  surface 
in  the  fire-box;  by  «0433,  to  get  the  area  of 
grate ;  by  -309,  to  get  the  cubic  feet  of  water 
room  in  the  boiler ;  by  -182,  to  get  the  cubic 
feet  of  steam  room  in  the  boiler. 

All  the  engines  of  which  proportions  are 
given  in  the  preceding  table,  have  four  driving 
wheels  and  truck,  with  the  exception  of  the 
engine  by  Hinkley  &  Drury,  having  13J-inch 
cylinders ;  this  engine  has  four  driving  wheels, 
upon  which  the  whole  weight  of  the  engine 
rests. 

An  engine  lately  constructed  by  Robert  Ste- 

phenson  &  Co.,  Newcastle-upon-Tyne,  England, 

may  be  taken  in  comparison  with  the  foregoing. 

This   engine   had   two   pair   of  5-feet  drivers 

and  one  pair  of  leading  wheels  : 

14-inch  cylinder : 

21-inch  stroke : 

50  square  feet  fire  surface  in  fire-box : 

9-91        "         "         "      on  grate : 
640  "         "         "      in  tubes : 

76.86  cubic  feet  water  in  boiler  and  around  fire- 
box. 


THE    LOCOMOTIVE    ENGINE.  57 

43  cubic  feet  steam  in  boiler  and  dome : 
7.5  «      "     steam  used  at  one  rev.  of  drivers. 

As  a  further  illustration  of  English  locomo- 
tives, we  will  give  the  dimensions  of  an  engine 
built  by  Bury,  Curtis  and  Kennedy,  of  Liver- 
pool, for  the  Birmingham  and  Shrewsbury  (nar- 
row gauge)  railway. 

15-inch  cylinder;  20-inch  stroke;  one  pair 
of  5  ft.  7  in.  driving  wheels  ;  one  pair  4  ft.  1  in. 
leading,  and  one  pair  3  ft.  7  in.  trailing  wheels. 

Boiler  shell  47  inches,  smallest  inside  diameter, 
and  containing  172  IJ-inch  tubes,  11  ft.  6  in. 
long.  Grate,  50J  in.  long,  by  42  in.  wide,  and 
55  inches  from  crown  sheet. 

Induction  ports,  12  by  l^  in.  Exhaust  port, 
3  J  in.  wide.  Single  blast  pipe,  4J  in.  at  mouth. 
Cylinders,  23J  in.  between  centres.  Bearings  of 
driving  axle,  8  in.  long  and  7  in.  in  diameter. 

The  heating  surface  of  locomotive  boilers  has 
of  late  years  been  considerably  increased,  not 
only  having  been  extended  with  the  enlargement 
of  the  cylinders  but  in  a  much  higher  ratio.  In 
some  recent  17-inch  cylinder  engines,  constructed 
at  Taunton  for  the  New  York  and  Erie  railroad, 
the  fire-box  surface  included  about  90  square  feet, 


58  THE   LOCOMOTIVE    ENGINE. 

while  tlie  tube  surface  fell  but  little  short  of  1000 
superficial  feet. 

We  will  add  a  few  particulars  of  an  engine  for 
burning  bituminous  coal,  which  was  constructed 
for  the  Baltimore  and  Ohio  railroad  by  Thacher 
Perkins,  master  of  machinery  on  that  road.  The 
performance  of  this  engine  during  the  year  1849 
was  upward  of  23,000  miles,  and  was  higher  than 
that  of  any  other  first-class  engine  on  that  road 
for  the  same  time. 

The  diameter  of  the  cylinder  was  17  inches; 
stroke  of  piston  22  inches;  four  pairs  of  driving- 
wheels  having  chilled  tires  43  inches  in  diameter. 
The  diameter  of  the  boiler  was  44  inches,  and 
there  were  125  wrought  iron  tubes,  12  feet  6 
inches  long,  and  2J-  diameter  at  the  fire-box  end, 
and  2-f  diameter  at  the  smoke-box  ends  of  same. 
The  grate  was  37J  inches  long,  by  41J  inches 
wide,  and  the  inside  depth  from  crown  sheet  to 
grate  was  50  inches.  Attached  to  the  boiler  of 
this  .engine  was  the  patent  apparatus  for  heating 
the  feed  water  by  the  surplus  exhaust  steam  of 
the  engine,  which  was  invented  by  Mr.  Perkins. 
The  exhaust  steam  from  both  cylinders  enters  a 
square  box  in  the  centre  of  the  smoke-box.  In 


THE   LOCOMOTIVE   ENGINE.  59 

this  box  is  a  movable  valve  by  which  the  steam 
can  be  discharged  through  the  ordinary  blast- 
pipes,  or  turned  into  a  pipe  leading  to  a  steam 
casing  surrounding  the  smoke-box.  This  pipe 
also  continues  along  beneath  the  boiler,  and  is 
united  to  a  steam  belt  surrounding  the  same  at 
the  fire-box  end,  and  from  which  the  steam  finally 
escapes  through  a  pipe  for  that  purpose.  The 
feed  water  can  be  admitted  directly  to  the  boiler, 
near  the  fire-box  end  of  this  pipe,  or,  which  is 
intended  in  running,  it  can  be  pumped  into  a 
casing  surrounding  this  pipe,  from  whence  it 
passes  into  a  water  casing  surrounding  the  smoke- 
box,  and  within  the  steam  casing  already  men- 
tioned. From  here  it  passes  into  the  boiler  a 
little  below  the  water  level,  at  the  smoke-box  end. 
In  this  arrangement  the  movable  valve  in  the 
steam-box  can  be  regulated  to  discharge  steam 
enough  through  the  blast-pipes  for  all  ordinary 
purposes  of  draught,  and  also  to  maintain  a  flow 
of  steam  through  the  pipe  beneath  the  boiler. 
The  feed  water  receives  a  large  portion  of  the 
heat  of  this  steam,  from  its  contact  with  it  in  the 
casing  surrounding  the  pipe,  and,  retaining  the 
heat  so*obtained,  it  passes  into  the  water  casing 


60  THE   LOCOMOTIVE   ENGINE. 

in  the  smoke-box,  where  it  is  exposed  to  the  heat 
of  the  waste  steam  on  the  outside,  and  to  the 
temperature  of  the  smoke-box  within.  It  thus, 
when  finally  admitted  to  the  boiler,  has  become 
heated  quite  to  the  boiling  point,  as  the  heat 
within  the  smoke-box  of  a  coal  engine  is  very- 
great,  even  with  long  tubes.  This  arrangement 
operates  as  a  variable  exhaust  by  allowing  any 
portion  of  the  waste  steam  to  be  turned  off  from 
the  blast-pipes;  it  effects  a  considerable  eco- 
nomy in  fuel  by  giving  the  water  to  the  boiler 
already  heated  very  hot ;  and  the  water  casing 
surrounding  the  smoke-box  prevents  the  destruc- 
tion of  the  latter  by  the  heat  emitted  from  the 
tubes. 

In  the  details  of  this  engine  the  expansion  valve 
was  worked  from  the  backing  eccentric,  and  one 
lever  sufficed  for  reversing  the  engine  and  throw- 
ing on  the  cut-off.  This  was  effected^y  making 
the  cut-off  rocker  arm  work  as  a  shell  on  the 
main  valve  rocker  shaft,  the  cams  for  throwing 
out  all  the  hooks  being  on  the  same  cam  shaft, 
and  that  for  the  forward  hook  being  only  a  quar- 
ter cam,  so  as  to  allow  that  hook  to  be  on  its 
pin  in  the  rocker  arm  in  two  positions  of  the  re- 


THE   LOCOMOTIVE    ENGINE. 


61 


versing  lever ;  that  is  to  say,  going  forward  with 
the  cut-off  on,  and  forward  with  it  off. 

The  patent  for  the  heating  apparatus  described  is  owned 
by  L.  B.  Tyng,  of  Lowell,  who  has  drawings  and  models 
showing  the  application  of  the  same  to  coal  and  to  wood  en- 
gines. For  coal  engines  some  arrangement  of  this  nature 
seems  obviously  necessary,  while  for  wood  engines  having  a 
large  extent  of  tube  surface,  with  moderate  length  of  tubes, 
the  application  of  this  invention  appears  to  promise  a  con- 
siderable economy  in  fuel.  The  apparatus  may  be  simplified 
in  wood  engines  by  pumping  the  water  directly  into  a  single 
casing  about  the  smoke-box,  and  withdrawing  the  contact 
of  the  exhaust  steam  by  suffering  it  to  pass  entirely  up  the 
chimney. 


faff  17  BE  SI  IT] 

4iJFO?^ 


SECTION    IV. 

DETAILS  OF  THE  LOCOMOTIVE  ENGINE  CONTINUED. 
OF  THE  CYLINDERS,  STEAM  CHESTS,  VALVES, 
AND  STEAM  PIPES. 

THE  casting  for  a  cylinder  must  be  perfectly 
sound;  and  this,  indeed,  is  requisite  for  all  the 
castings  of  a  locomotive.  The  thickness  of  a 
cylinder,  after  boring,  is  from  f  to  |  inch,  and 
about  T3g  inch  are  taken  off  all  around  by  the  cut- 
ter of  the  boring  bar.  No  cylinder  can  be  truly 
and  accurately  bored  in  a  boring  lathe,  unless  the 
latter  be  strong  and  steady.  The  thickness  of 
the  flange  of  the  cylinder  is  1J  inch  or  more. 
The  flange  by  which  it  is  secured  to  the  frame  is 
1J  inches  thick,  and  as  long  as  the  distance  be- 
tween the  flanges  to  which  the  cylinder  heads  are 
bolted.  Four  or  five  one-inch  bolts  are  sufficient 
to  secure  this  flange  to  the  frame.  The  cylinders 
are  generally  cast  separately,  and  are  united  by 
a  bar  of  iron  4  by  1J  inches,  bolted  to  a  project- 
ing flange  on  each.  In  one  or  two  instances  we 

62 


THE    LOCOMOTIVE   ENGINE.  63 

have  seen  them  cast  together,  but  this  method 
makes  rather  an  awkward  casting  to  mould,  to 
bore,  and  to  fit,  yet  it  removes  the  artificial  con- 
nection which  is  otherwise  necessary. 

The  faces  of  the  cylinder  and  valve  require  to 
be  ground  perfectly  smooth  and  flat,  which  is 
done  by  closing  the  ports  with  blocks  of  wood,  as 
also  the  cavity  in  the  valve  ;  they  are  then  ground 
together  with  fine  sharp  sand  and  water,  finishing 
off  with  emery  and  oil.  The  stuffing  boxes  for 
the  piston  rods  and  valve  stems  require  a  brass 
lining  filled  with  Babbitt  metal.  The  valves  are 
generally  of  cast  iron,  but  sometimes  of  brass. 

The  valve  stem  in  Hinkley's  engines  is  laid  in 
a  deep  recess  in  the  upper  side  of  the  valve,  and 
has  nuts  and  check  nuts  screwed  against  each 
side  of  same.  The  valve  is  sometimes  encircled 
by  a  wrought  iron  hoop  or  spectacle  J  inch  in 
thickness,  but  increased  to  1J  inches  on  one  side, 
and  has  the  valve  stem  tapped  into  it. 

The  expansion  valve  is  often  worked  directly 
on  the  top  of  the  port  valve.  When  no  expansion 
is  sought,  the  cut-off  valve  rod  is  placed  in  con- 
nection with  the  port  valve  rod,  and,  acquiring 
the  motion  of  the  latter,  is  relatively  at  rest  with 


64  THE   LOCOMOTIVE    ENGINE. 

it.  Other  makers  have  the  cut-off  valve  over  the 
port  valve,  and  in  the  same  chest  with  it,  but 
interpose  a  plate  with  valve  ports  between  the 
two  valves.  It  is,  however,  difficult  to  get  at  the 
valves  where  they  are  so  placed,  unless  the  engine 
has  outside  cylinders,  or  has  its  steam  chest 
covers  taken  off  from  the  outside.  Hinkley's 
latest  engines  have  covers  on  the  side  of  the  valve 
chest,  which  are  removed  from  the  outside  of  the 
smoke-box.  But  the  opening  on  the  side  of  the 
chest  is  no  larger  than  to  allow  of  taking  out  the 
valve,  not  being  large  enough  to  allow  of  setting 
the  valves  when  it  becomes  necessary  to  do  so, 
except  by  taking  off  the  entire  chest.  In  Hink- 
ley's engines,  the  cut-off  valve,  when  not  required 
to  be  used,  is  thrown  entirely  off  the  ports,  to 
prevent  any  obstruction  to  the  passage  of  the 
steam.  This  is  effected  by  an  arm  on  the  revers- 
ing cam  shaft,  which,  when  the  cut-off  hooks  are 
thrown  out,  throws  the  lower  rocker  arm,  which 
works  the  cut-off  valve,  entirely  over,  and  carries 
the  valve  off  its  ports. 

The  valve  seat  requires  to  be  slightly  raised 
above  the  face  of  the  casting  on  which  it  is 
formed,  that  any  foreign  substance  received  by 


THE   LOCOMOTIVE   ENGINE.  65 

the  steam  pipe  may  be  pushed  off  by  the  valve 
without  scratching  the  valve  face. 

Steam  chests  are  generally  of  a  square  or  ob- 
long form,  and  in  inside  cylinder  engines  are 
enclosed  within  the  smoke-box.  In  Souther's  en- 
gines, however,  the  steam  chest  is  round,  and 
projects  outward,  so  that  the  valve  face  is  inclined 
at  an  angle  of  about  45°, — the  smoke-box  being 
made  round,  as  a  continuation  of  the  boiler.  By 
this  arrangement  he  secures  the  advantage  of  a 
ground  joint  for  the  steam  chest  cover,  and  ready 
access  to  the  valves  of  the  engine.  A  ground 
joint  is  cheaper  than  a  filed  joint,  and  better  than 
a  putty  joint.  The  cylinders  and  chests,  however, 
from  not  being  enclosed  in  the  smoke-box,  are 
exposed  to  the  cold  air,  which  not  unfrequently, 
especially  in  winter,  operates  to  condense  the 
steam  to  an  inconvenient  degree.  The  steam 
chests,  however,  have  a  jacket  or  casing  over 
them,  and  the  cylinders  might  be  lagged  so  as  to 
make  this  a  trifling  objection. 

The  steam  pipe  is  made  of  thick  copper,  united 
at  one  end  to  the  vertical  cast  iron  pipe  entering 
the  dome,  and  at  the  other  end  to  a  pipe  casting 

formed  to  make  a  tight  joint  with  the  smoke-box 
6* 


66  THE   LOCOMOTIVE   ENGINE. 

sheet.  The  steam  passes  through  this  tee  piece, 
and  then  branches  off  to  each  cylinder.  All  the 
joints  about  the  steam  pipe  should  -be  ground 
turning  joints.  Hangers  of  wrought  iron  must  be 
made  to  support  the  steam  pipe  in  its  place. 
The  area  of  the  steam  pipe  should  equal  the  area 
of  two  of  the  induction  ports  to  the  cylinder,  and 
each  branch  pipe  should  have  half  this  area.  The 
exhaust  pipes  should  have  nearly  the  same  area 
as  the  exhaust  ports,  until  we  come  to  the  copper 
pipe  attached  as  a  mouth  or  blast  pipe.  This 
pipe  at  its  largest  place  should  be  considerably 
smaller  than  the  eduction  port,  and  at  its  mouth 
requires  to  be  reduced  to  about  two  inches  in 
diameter.  Most  of  Hinkley's  15-inch  cylinder 
engines  are  running  with  their  exhaust  pipes  con- 
tracted to  IJ-inch  diameter  at  the  mouth.  For 
16-inch  cylinders,  the  blast  pipe  is  2  in.  to  2^  in. 
English  engineers  are  of  opinion  that  the  fire  sur- 
face of  an  engine  should  be  very  much  increased,* 
in  order  that  a  proper  natural  draft  may  exist 
without  requiring  so  great  a  reduction  in  'the  blast 


*  Dimensions  of  engine,  by  Bury,  Curtis,  and  Kennedy,  on 
page  57. 


THE   LOCOMOTIVE   ENGINE.  67 

pipe.  The  resistance  offered  to  the  progress  of 
the  piston  at  high  speeds,  arising  from  the  con- 
traction of  the  blast  pipes,  has  been  stated  by 
Stephenson,  of  Newcastle,  to  absorb  one-half  the 
power  of  an  engine.  It  appears  to  us  that  a  large 
extent  of  heating  surface,  with  the  use  of  some 
simple  expedient  for  regulating  the  draft,  would 
produce  very  favourable  results  in  the  perform- 
ances of  locomotives.  It  has  been  proposed, 
instead  of  varying  the  mouth  of  the  blast  pipe,  to 
establish  a  communication  between  the  exhaust 
steam  and  the  feed  water  of  the  boiler,  by  which 
means  the  draft  could  be  regulated  by  turning  off 
any  part  of  the  exhaust  to  heat  the  water.  This 
plan,  however,  involves  considerable  complication, 
and  cannot  be  regarded  as  eminently  practical. 
We  have  no  doubt,  however,  that  some  simple  ex- 
pedient will  be  devised  for  accomplishing  so  de- 
sirable an  object. 


SECTION  V. 

DETAILS  OF  THE  LOCOMOTIVE  ENGINE  CONTINUED. 
— OF  THE  FRAMING,  JAWS,  WHEELS,  SPRINGS, 
&C. 

THE  framing  of  all  the  engines  now  built  in 
this  country  is  between  the  wheels,  and  rests  on 
the  bearings  of  the  axles  of  the  same,  through 
the  intervention  of  steel  springs.  The  frames 
of  the  most  recent  descriptions  of  locomotives 
are  solid,  and  have  the  jaws  for  the  bearings 
either  forged  with  them,  or  forged  separately 
and  secured  to  the  frame  by  bolts.  Many  of 
these  solid  frames  are  extremely  light.  The 
most  usual  kind  of  frame,  however,  is  the  riveted 
frame.  Two  plates  of  flat  iron,  say  5  by  f  inch, 
with  a  bar  2  inches  square  riveted  between  them 
so  that  one  of  its  sides  is  flush  with  the  upper 
edges  of  the  plates.  In  Hinkley's  engines,  and 
in  most  others,  the  frame  passes  over  the  bear- 
ings, and  is  dropped  down  immediately  in  front 
of  the  forward  driving  axle,  to  the  level  of  the 

68 


THE    LOCOMOTIVE    ENGINE.  69 

centres  of  the  cylinders,  and  continues  at  that 
level  to  the  forward  end  of  the  engine.  This 
mode  of  reducing  the  height  of  the  frame  at  the 
forward  end,  gives  a  ready  access  to  the  work 
of  the  machine.  She  jaws  to  this  frame*  are 
of  cast  iron,  and  are  secured  by  bolts  passing 
up  through  a  stout  rib  on  the  upper  side  of  the 
jaw,  and  the  2-inch  bar  which  is  riveted  in  the 
frame.  Cast-iron  jaws,  to  stand,  require  to  be 
very  heavy.  On  the  "Baldwin"  and  "Whis- 
tler," (engines  on  the  Lowell  road,  built  at 
Lowell,)  the  want  of  strength  in  their  jaws, 
which  were  of  cast  iron,  and  were  continually 
breaking,  made  it  necessary  to  replace  them 
with  a  set  of  wrought  iron  jaws.  A  stout  cast 
iron  thimble  is  placed  between  the  back  and 
foward  jaws ;  also  short  thimbles  between  the 
two  cheeks  of  each  jaw,  and  a  IJ-inch  bolt  is 
then  passed  through  the  whole,  and  has  stout 
nuts  at  each  end  to  secure  it.  Diagonal  braces 
also  pass  from  the  ends  of  this  bolt  up  to  the 
frame,  thus  forming  a  complete  truss. 

Engine  wheels  with  rims  cast  in  sand  have 
solid  hubs.  Winans's  wheels  with  chilled  rims 
have  the  hubs  cast  with  core  prints,  leaving 


70  THE   LOCOMOTIVE    ENGINE. 

three  open  slots  throughout  their  thickness. 
After  the  rim  has  cooled,  these  are  filled  tight 
with  blocks  of  wrought  iron,  and  the  whole 
hub  is  then  encircled  with  a  strong  wrought 
iron  band.  In  the  rims  o£  his  chilled  wheels 
he  casts  a  ring  of  wrought  iron,  to  assist  the 
strength  of  the  rim;  both  to  keep  it  from 
breaking,  and  to  hold  the  rim  from  flying  apart 
in  case  it  should  crack.  Wrought  iron  tires 
have  been  exclusively  used  for  drivers  until 
the  introduction  of  Winans's  chilled  rims,  and 
the  later  method  of  using  chilled  cast  iron  tires, 
which  were  first  used,  we  believe,  by  Thacher 
Perkins,  now  master  of  machinery  on  the  Balti- 
more and  Ohio  Railroad.  To  put  on  a  wrought 
tire,  it  is  first  evenly  heated  to  a  moderate  heat, 
then  dropped  on  the  rim  of  the  wheel  and 
quickly  cooled  by  throwing  on  cold  water. 
Seven  or  eight  bolts  with  riveted  heads  are 
then  passed  through  the  tire  and  rim,  to  secure 
the  tire  from  working  off.  To  remove  a  tire,  the 
bolts  through  the  rim  must  be  taken  out,  or,  if 
rivets  are  used,  they  must  be  drilled  out:  the 
wheel  is  then  laid  on  a  circular  mound  of  earth, 
a  few  inches  high  and  nearly  as  large  as  the 


THE    LOCOMOTIVE    ENGINE.  71 

wheel;  a  steady  but  moderate  heat  is  applied 
directly  to  the  tire,  the  body  of  the  wheel  being 
covered  with  earth,  and  in  a  few  minutes  the 
wheel  may  be  lifted  out  of  the  tire,  by  means 
of  a  crane.  In  this  manner  the  tires  are  taken 
from  a  pair  of  wheels  without  removing  them 
from  the  axle,  by  turning  the  axle  up  on  one 
end  so  as  to  bring  one  wheel  on  its  side. 

The  chilled  tires,  when  properly  cast,  are 
better  for  some  reasons  than  chilled  rims ;  but 
it  has  not  yet  been  satisfactorily  ascertained 
whether  either  can  take  the  place  of  wrought 
iron  tires.  The  main  difficulty  anticipated  in 
their  use  is  an  insufficient  adhesion  to  the  rails, 
especially  in  winter,  when  the  rails  are  frosty  or 
damp.  The  milder  climate  of  the  Southern 
States  has  prevented  this  from  becoming  so 
serious  an  objection  to  their  adoption  there. 
The  chilled  tires  are  three  inches  thick,  and  are 
bolted  to  the  rim  of  the  wheel.  The  merits  of 
'these  tires  above  those  of  chilled  rims  or  chilled 
wheels  are,  that  if  a  tire  breaks  ft  can  be  re- 
placed without  throwing  away  the  wheel,  and 
they  are  also  readily  renewed  when  worn  out; 
whereas,  with  a  chilled  wheel,  it  is  useless  when 


72  THE    LOCOMOTIVE    ENGINE. 

the  rim  becomes  much  worn,  though  the  rest  of 
the  wheel  is  perfectly  sound  and  whole. 

Chilled  wheels  are  used  almost  entirely  for 
trucks,  tenders,  and  cars.  Engine  trucks  are 
generally  30  inches  in  diameter,  and  car  wheels 
33  inches.  Some  of  the  roads  running  out  of 
Boston  have  imported  sets  of  wrought  iron 
wheels  from  England,  and  placed  them  under 
their  cars  for  trial.  On  the  Boston  and  Provi- 
dence road  we  have  seen  a  pattern  of  cast 
wheel  with  wrought  tire,  and  having  a  ring  of 
hard  wood,  two  inches  thick,  between  the  tire 
and  rim  of  the  wheel.  On  the  above  road  they 
are  placing  these  wheels  generally  under  their 
passenger  cars. 

Engine  trucks  and  car  wheels  are  usually 
secured  to  their  axles  by  one  stout  spline,  and 
the  driving  wheels  by  two  one-inch  square  keys. 

The  cranked  axle  is  forged  from  a  bar  which 
is  kinked  or  upset  by  doubling  or  bending,  so  as 
to  form  the  blocks  for  the  cranks  on  one  side  of 
the  axle.  The  axle  is  then  twisted  between  the 
cranks  till  they  are  at  right  angles  with  each 
other.  The  crank  wrist  is  formed  by  drilling 
out  a  sufficient  portion  of  the  block,  left  in 


THE   LOCOMOTIVE   ENGINE.  73 

the  manufacture  of  the  axle,  and  then  finished 
by  turning. 

The  cases  for  the  bearings  of  Hinkley's  en- 
gines have  dowels  of  a  composition  of  equal 
parts  of  copper  and  tin,  inserted  in  the  case  in 
the  direction  of  the  length  of  the  bearing.  The 
space  between  these  dowels  is  filled  with  Babbitt 
metal.  The  dripper  or  cup  has  flanges  to  hold 
it  in  the  case,  and  is  kept  in  position  by  a  screw 
pressing  against  its  under  side. 

There  is  a  stout  spring  over  each  driver,  hav- 
ing one  end  attached  by  a  loop  to  the  frame,  and 
the  other  to  a  bar  between  the  drivers,  which 
turns  on  a  pin  beneath  the  frame.  The  object 
of  this  bar  is  to  equalize  any  effects  arising 
from  inequalities  on  the  rail,  by  transmitting  a 
portion  of  the  shock  to  the  wheel  which  is  re- 
moved from  this  inequality.  The  lower  end  of 
the  loop-ended  rod  attached  to  the  spring  should 
be  secured  in  the  end  of  the  equalizing  bar  by  a 
pin,  as  the  rod  is  apt  to  break  off  close  to  the 
nuts  where  these  are  used.  The  equalizing  bar 
is  of  wrought  iron,  and  for  strength  must  be 
made  deeper  in  the  centre  than  at  the  ends. 

The   springs    are    generally  from    27   to    34 


74  THE   LOCOMOTIVE   ENGINE. 

inches  in  length,  and  are  formed  of  plates  of  J, 
T5e>  or  f  inch  steel,  and  sometimes  plates  of  each 
size.  A  spring  of  the  proper  form,  30  inches 
long,  and  having  14  plates  of  T5ff,  and  two  plates 
at  the  back  of  f  inch  steel,  and  3  inches  wide, 
makes  a  good  spring  for  a  driver.  A  tit  or  pro- 
jection is  made  in  the  end  of  each  leaf,  to  fit  in 
a  punched  opening  in  the  leaf  below.  This  is  to 
prevent  any  side  motion  or  displacement  among 
the  leaves  of  the  spring.  The  end  of  the  upper 
leaf  is  turned  up  to  prevent  the  loop  which 
passes  over  the  end  of  the  spring  from  slipping 
off. 

Rogers,  Ketchum  and  Grosvenor  have  used 
J-inch  iron  plates,  six  or  eight  inches  long,  in- 
terposed between  the  leaves  at  the  middle  of  the 
spring.  The  leaves  of  the  spring,  when  not 
under  pressure,  are  in  contact  only  at  their  ends ; 
but  on  the  application  of  any  weight  acting  upon 
them,  are  brought  into  contact  for  several  inches 
of  their  length.  This  spring,  adapted  to  any 
load,  is  an  English  idea. 

India-rubber  springs  have  been  applied  to 
the  driving  wheels  of  light  engines,  and  in  many 
cases  to  the  truck  and  tender  wheels.  They 


THE   LOCOMOTIVE   ENGINE.  75 

make,  at  least,  a  very  cheap  spring,  and  have 
proved  well. 

The  iron  truck  frames  in  general  use  have  in- 
side bearings.  They  are  formed  of  f^-inch  plates, 
with  wrought-iron  bars  or  thimbles  riveted  be- 
tween them.  The  side  bars  are  made  to  clasp 
the  brass  boxes  enclosing  the  bearing  of  the  axle. 
A  large  inverted  spring  at  each  side  has  one  end 
resting  over  the  bearing  of  each  axle,  and  sup- 
ports the  frame  on  its  upper  side.  The  under 
side  of  the  frame  is  faced  with  a  plate  of  steel, 
where  it  rests  upon  the  spring.  The  construction 
of  this  truck  does  not  admit  of  any  one  of  the 
wheels  rising  without  raising  the  whole  frame. 
Norris,  and  some  other  makers,  however,  make 
the  action  of  the  truck  wheels  independent  of 
each  other,  by  making  what  is  called  a  live  truck 
frame.  In  this  frame  the  spring,  instead  of  rest- 
ing directly  on  the  frame,  rests  on  the  bearing  by 
a  pintal  passing  through  the  frame.  Any  shock 
of  the  forward  wheel  is  thus  divided,  and  partly 
transmitted  through  the  spring  to  the  hind  wheel. 
The  Lowell  Machine  Shop  use  a  truck  frame,  with 
outside  bearings,  on  one  of  their  patterns. 

The  bearings  of  the  truck  axles  are  from  3J  to 


76  THE   LOCOMOTIVE   ENGINE. 

3|  inches  in  diameter,  and  5J  inches  long.  The 
bearings  of  the  driving  axle  are  from  6  to  7  inches 
in  diameter  and  6  inches  long.  The  crank  wrists 
are  of  the  same  diameter  as  the  bearings,  and 
are  3J  to  4  inches  wide.  The  cheeks  of  the 
cranks  are  5  inches  thick. 

The  pintal  bushing  for  the  truck  is  of  cast 
iron,  and  is  riveted  between  the  plates  forming 
the  truck  frame.  The  pintal  is  secured  to  the 
boiler  behind  the  cylinders,  or  is  made  fast  to 
the  cylinders  themselves,  by  being  passed  through 
the  flanges  connecting  them  together,  and  se- 
cured by  a  shoulder  below  and  a  nut  above.  The 
pintal  is  about  5  inches  in  diameter. 

There  should  be  a  slide  and  wedge  between  the 
footboard  and  tender,  to  prevent  jarring  and  jolt- 
ing. This  wedge  is  drawn  up  in  the  slide  by  a 
screw  and  nut. 

There  is  generally  a  rail,  or  outside  frame,  as 
it  is  sometimes  termed,  outside  of  the  wheels. 
This  outside  frame  makes  a  convenient  support 
for  the  pump,  and  serves  to  make  a  walk  or  bal- 
cony by  which  to  go  to  the  forward  end  of  the 
engine  when  it  is  running.  This  outside  frame, 
if  mounted  with  jaws  and  springs,  might  give 


THE   LOCOMOTIVE   ENGINE.  77 

additional  support  for  the  driving  axle,  and  would 
assist  the  strength  of  the  inside  frame.  The 
eccentrics  could  be  placed  outside  the  wheels, 
and  wrought  iron  cranks  would  be  keyed  to  the 
axle  outside  of  the  frame,  to  connect  the  drivers. 
There  is  no  great  practical  difficulty,  in  our 
opinion,  in  keeping  four  bearings  in  line  on  the 
same  axle. 

It  appears  to  us  that  a  very  light  and  strong 
tender  frame  could  be  made  of  flat  bars  3J  by  1J 
inches,  and  which  would  cost  no  more  than  our 
present  heavily  timbered  wooden  ones. 


SECTION  VI. 

DETAILS  OF  THE  LOCOMOTIVE  ENGINE  CONTINUED. 
— OP  THE  PISTONS,  SLIDES,  CONNECTING  KODS, 
VALVE  MOTION,  AND  PUMPS. 

THE  pistons  generally  have  two  outside  rings, 
while  some  makers,  as  Norris  and  others,  use 
three.  These  rings  are  sometimes  of  cast  iron, 
and  sometimes  of  composition.  The  piston  rings 
used  on  the  Boston  and  Maine  road  are  made 
from  a  composition  of  80  parts  copper  and  20 
parts  tin.  The  outside  rings  are  sometimes  cut 
in  four  pieces,  and  are  sometimes  cut  open  only 
on  one  side.  Cast  iron  rings,  if  not  set  out  too 
tight  against  the  inside  *f  the  cylinder,  may  be 
regarded  as  not  only  cheaper,  but  better  than 
composition  rings.  And  rings  simply  cut  open, 
are  better,  for  most  reasons,  than  those  which 
are  cut  in  three  or  four  pieces.  The  cover  is 
usually  secured  to  the  body  of  the  piston  by  four 
screws.  The  following  are  the  dimensions  of 
Hinkley's  15-inch  pistons  on  the  Maine  road,  and 

78 


THE   LOCOMOTIVE   ENGINE.  79 

Laving  the  kind  of  packing-rings  described  as 
used  by  that  road.  Diam.  of  follower  or  cover, 
14{f  in.;  diam.  of  outside  rings,  before  cutting 
open,  15T3g  in.;  thickness  of  piston,  4|  in.;  thick- 
ness of  follower,  f  in.;  thickness  of  outside  rings, 
f  in.;  depth  of  do.,  !T9g  in.;  inside  ring  of  cast 
iron,  f  thick.  Four  screws  to  secure  cover,  each 
one  inch  in  diameter,  3  in.  under  head,  and 
having  heads  1 J  in.  square.  Each  screw  is  5f  in. 
from  centre  of  piston.  Four  springs  to  set  out 
packing,  each  6  in.  long,  3  in.  wide,  T3g  in.  thick 
at  thickest  part,  and  having  a  bend  or  deflection 
of  f  in.  Screws  to  set  out  packing,  f  in.  diam. 
Key  to  secure  piston  rod,  If  by  -J-J.  Thickness 
of  iron  around  rod,  If  in.;  diam.  of  body  of  iron 
penetrated  by  screws  to  secure  cover,  is  2  in.,  and 
is  connected  to  the  hub  of  the  piston  head  by  a 
bridge  of  iron  J  in.  thick. 

Winans's  17-inch  piston  has  six  screws  to  secure 
the  cover,  and  each  spring  which  is  set  out  by  the 
packing  screws,  presses  at  each  end  against  the 
centre  of  a  smaller  spring,  thus  making  24  bear- 
ings against  the  packing  rings. 

All  this  is  unnecessary,  and  makes  the  springs 
liable  to  derangement.  Norris's  springs  are  9 


80  THE   LOCOMOTIVE   ENGINE. 

inches  long,  there  being  three  in  his  14-inch 
piston. 

The  best  slides  are  undoubtedly  the  flat  slides 
first  used  in  the  old  Locks  and  Canals  Co.'s  en- 
gines. These  are  now  used  by  Rogers  and  others. 
The  simplest  and  cheapest  form  of  slide  is  the 
round  slide  used  by  Norris,  and  until  recently  by 
Hinkley.  The  length  of  cross-head  bearing  on 
the  slides  is  generally  10  or  12  inches.  The 
diameter  of  the  round  slides  is  2|  inches.  One 
end  of  the  slides  is  attached  to  lugs  on  the  cylin- 
der cover,  the  other  to  a  wrought  iron  loop  sup- 
ported by  a  cross  girt  under  the  boiler. 

The  connecting  rods  have  oval  or  octagonal 
boxes  on  the  outward  sides  of  the  bearings,  and 
square  boxes  on  the  inner  sides,  or  where  they 
abut  against  the  end  of  the  rod.  The  straps  are 
generally  1  in.  to  1J  in.  thick,  and  in  width  2J  in. 
at  the  crank  end,  and  2J  in.  at  the  cross-head 
end.  The  straps  are  secured  by  two  J  in.  bolts 
to  each,  and  the  boxes  are  set  up  by  a  key  gene- 
rally 1  j  and  f  inch  wide  and  f  thick  at  the  crank 
end,  and  by  a  somewhat  smaller  key  at  the  cross- 
head  end.  The  most  recent  method  of  securing 
the  key  in  its  place  is  to  have  its  smaller  end 


THE   LOCOMOTIVE    ENGINE.  81 

pass  through  a  piece  of  iron,  on  the  outside  of 
the  strap,  and  an  inch  thick;  this  piece  being 
secured  to  the  strap  by  one  of  the  bolts  already 
noticed.  A  set  screw  in  this  piece  pinches  the 
end  of  the  key,  while  another  screw  at  the  centre 
of  the  flat  face  of  the  rod  is  turned  against  the 
key  at  that  point.  The  rod  is  generally  not  far 
from  six  feet  between  the  centres,  and  is  nearly 
or  quite  3  inches  in  diameter  at  the  centre.  The 
cross-head  bearing,  when  of  cast  iron,  is  2 J  inches 
in  diameter, 

As  the  boxes  in  the  connecting  rod  become 
worn,  the  setting  them  up  by  the  keys  tends  to 
lengthen  the  rod,  as  the  outside  boxes  retain 
their  places,  while  the  inside  boxes  are  moved 
outward.  In  the  main  connecting  rod  this  is  no 
great  evil,  as  there  is  generally  sufficient  allow- 
ance at  the  end  of  the  cylinder  for  the  piston  to 
work  up  a  little  without  hitting  the  head ;  and  for 
this  purpose  there  should  be  more  clearance  given 
at  the  forward  end  of  the  cylinder  than  at  the 
hind  end ;  say,  on  a  new  engine,  J  in.  allowance 
at  the  hind  end,  and  nearly  J  inch  on  the  forward 
end.  On  the  rods,  however,  to  connect  the 
drivers  together,  it  is  essential  that  the  original 


82  THE   LOCOMOTIVE   ENGINE. 

length  of  the  rod  be  constantly  preserved;  and 
to  do  this,  the  key  at  one  end  of  the  rod  presses 
the  inner  box  outward,  while  the  other  key,  being 
outside  the  box  at  that  end  of  the  rod,  presses  the 
outer  box  inward.  On  Winans's  and  on  Perkins's 
engines,  having  four  pairs  of  wheels  to  connect, 
the  bearing  is  bored  out  of  -the  end  of  the  rod,  a 
tight  bushing  inserted,  and  no  keys  used. 

The  valve  motion  generally  used  is  the  indirect 
attachment  of  the  eccentric,  through  the  rocker 
shaft.  In  ordinary  inside  cylinder  engines,  a 
shaft  1  {•  inches  in  diameter  is  secured  by  stands 
to  the  cross  girt  supporting  the  slides.  On  this 
shaft  there  are  two  wrought  iron  tubes  or  shells, 
one  for  receiving  and  communicating  the  motion 
for  each  valve.  The  thickness  of  these  tubes  is 
f  inch.  The  rocker  arms  which  support  the 
hooks  are  6J-  inches  between  the  centres,  their 
hubs  f  to  f  inch  thick,  and  the  arms  are  f  inch 
thick.  The  pins  or  bolts  which  support  the  hooks 
have  thimbles  1J  in.  diameter,  and  T%  in.  thick. 
The  rocker  shaft,  tubes,  arms,  and  thimbles,  are 
all  of  wrought  iron.  (In  some  instances  cast  iron 
tubes,  with  the  arms  cast  therewith,  have  been 
used,  and  when  working  on  a  wrought  iron  shaft, 


THE   LOCOMOTIVE   ENGINE.  83 

have  less  friction  than  the  -wrought  iron  tubes. 
The  Taunton  Co.  have  used  cast  iron  rocker  tubes 
on  upwards  of  sixty  engines,  without  breakage.) 
The  pin  for  the  valve  stem  is  turned  with  a  shoul- 
der, and  is  passed  through  the  end  of  the  upper 
arm,  and  secured  by  a  nut  on  the  back  side  of 
same.  The  thickness  of  the  upper  arm  is  1J  to 
to  1J  inches,  and  is  of  the  same  length  as  the 
lower  arm.  The  arms  on  the  rocker  shaft,  which 
receive  the  motion  of  the  hand  hooks,  are  10 
inches  between  the  centres.  The  object  of  the 
hand  hooks  is  to  catch  the  eccentric  hooks  when 
the  engine  is  reversed,  and  also  to  assist  in  start- 
ing in  difficult  situations,  as  in  a  drift  of  snow. 
The  inside  of  the  eccentric  hooks,  where  they 
wear  on  the  thimbles  of  the  rocker  arms,  are 
faced  with  a  wedge  or  dowel  of  hardened  steel. 
The  eccentric  rods  are  1J  to  If  inches  in  diame- 
ter, and  have  right  and  left  nuts  to  adjust  their 
length.  The  end  of  the  rod  is  secured  to  the 
brass  hoop  or  eccentric  band  by  bolts,  or  by  be- 
ing passed  through  a  hub  formed  on  same,  with 
nuts  and  check  nuts  on  each  side.  The  eccentric 
band  is  1J  inches  thick,  and  is  lined  with  Babbitt 
metal.  The  eccentrics  generally  have  three  inches 


84  THE  LOCOMOTIVE   ENGINE. 

throw,  and,  in  inside  cylinder  engines,  must  be 
cast  in  two  pieces  to  allow  of  their  being  placed 
between  the  cranks.  The  eccentrics  are  secured 
to  the  axle  by  set  screws  turned  at  their  ends  to 
a  blunt  point,  and  entering  the  axle.  This  is  to 
give  a  chance  for  altering  the  lead  of  the  valve 
when  required,  which  could  not  be  so  readily  done 
were  the  eccentrics  keyed  to  the  axle.  It  is  for 
this  reason,  also,  that  the  eccentrics  are  gene- 
rally cast  separately,  although  some  engines  have 
the  four  eccentrics  for  forward  and  backward 
motion  for  each  valve  cast  in  one  piece,  or  at 
least  in  two  pieces,  to  put  together  around  the 
axle.  The  strap  under  the  hook  is  }  to  f  thick, 
and  long  enough  that  the  hook  may  traverse, 
when  thrown  out,  in  either  direction,  without 
striking  the  thimble  in  the  rocker  arms.  The 
cams  for  raising  the  hooks  are  of  cast  iron,  and 
have  a  throw  of  two  inches  or  more.  These  cams 
are  secured  to  a  wrought  iron  shaft  1J  to  1} 
inches  in  diameter,  having  a  pinion  of  12  or*  14 
teeth  on  one  end  and  turned  by  a  segment,  which 
is  worked  by  the  reversing  lever  on  the  footboard. 
The  expansion  valve  is  worked  through  the 
medium  of  a  separate  rocker  shaft,  having  also  a 


THE   LOCOMOTIVE   ENGINE.  85 

cam  shaft,  with  reversing  rod  to  work  the  same. 
As  this  cam  shaft  requires  to  be  turned  but  one 
quarter  around,  a  simple  arm  attached  to  it  is  all 
that  is  necessary. 

The  hooks  are  sometimes  formed  with  Y-shaped 
openings,  in  order  that  they  may  readily  catch 
the  pins  when  reversed. 

This  general  arrangement  of  operating  the 
valve  has  been  recently  superseded  in  a  measure 
by  the  introduction  of  Stephenson's  link  motion, 
although  the  old  establishments  still  adhere  to 
the  use  of  the  rocker  shaft.  An  open  curve,d 
link  is  attached  at  one  extremity  to  the  forward 
rod,  and  at  the  other  to  the  backing  rod  from  the 
eccentrics.  A  block  attached  to  the  valve  stem 
is  made  to  fit  this  link,  while  the  link  can  be 
raised  or  lowered  so  as  to  bring  this  block  within 
the  action  of  either  rod.  By  this  method,  when- 
ever the  engine  is  reversed,  the  ports  are  ready 
to  take  steam,  as  the  act  of  raising  or  lowering 
the  link  moves  the  valve  to  its  proper  position  on 
the  face  of  the  cylinder.  As  this  method  of 
working  the  valve  admits  of  giving  it  a  variable 
throw,  advantage  is  sometimes  taken  of  this  cir- 
cumstance to  work  expansively.  Indeed,  it  was 


86  THE   LOCOMOTIVE   ENGINE. 

for  this  purpose  that  Stephenson  first  secured  a 
patent  (in  England)  for  its  use.  The  valve,  how- 
ever, should  generally  have  a  determinate  throw, 
depending  on  the  size  of  the  ports  which  it  co- 
vers ;  and  any  increase  or  diminution  of  this 
throw  is  attended  with  a  choking  of  the  induction 
and  eduction  of  the  steam.  This  result  may  be 
made  evident  by  making  a  section  of  the  steam 
ports  on  the  side  of  a  small  piece  of  board  having 
its  edges  straight,  and  making  a  section  of  the 
valve  on  another  straight  piece  of  wood.  If  the 
edges  of  these  boards  are  applied  to  each  other, 
it  will  be  seen  that  any  other  travel  than  between 
2J  and  3J  inches,  would  not  readily  allow  of  the 
proper  passage  of  the  steam.  The  travel  of  the 
valve,  for  this  reason,  is  generally  fixed  at  3 
inches. 

A  modification  of  the  link  motion,  without  alter- 
ing, however,  its  essential  features,  was  devised 
by  Sharp,  Brothers  &  Co.,  of  Manchester,  Eng- 
land, and  applied  to  the  goods  engines  constructed 
by  them  for  the  Great  Western  Line.  The  link 
was  curved  the  opposite  way  to  Stephenson's,  his 
link  being  described  from  the  centre  of  the  axle, 
and  was  suspended  by  a  straight  link  to  the  boiler 


THE   LOCOMOTIVE   ENGINE.  87 

or  frame.  The  eccentric  rods  thus  retaining  one 
position,  the  block  was  attached  to  the  valve  stem 
by  a  jointed  arm,  and  was  raised  or  lowered  by  a 
lever  for  that  purpose.  There  are  more  joints 
about  this  arrangement  than  in  Stephenson's,  and 
its  only  merit  above  Stephenson's  is,  that  the 
jointed  valve  stem  may  be  raised  with  less  power 
than  the  whole  weight  of  the  eccentric  rods  and 
links.  The  use  of  this  motion  for  obtaining  a 
variable  expansion  is  of  course  liable  to  the  same 
objections  as  Stephenson's. 

A  form  of  variable  cut-off,  introduced  by  Horace 
Gray,  Esq.,  of  Boston,  upon  the  Fitchburg,  New 
York  and  Erie,  and  other  roads,  consists  in  an 
open  curved  link  formed  as  an  arm  on  the  upper 
side  of  the  cut-off  rocker  shaft.  The  cut-off  valve 
rod  being  jointed  near  the  stuffing-box,  and  at- 
tached to  a  block  in  this  link,  can  be  raised  or 
lowered  to  acquire  any  throw  within  the  limits 
of  motion  of  the  block.  By  this  method  a  va- 
riable expansion  is  obtained  without  affecting  the 
induction  or  eduction  of  steam  in  the  cylinder. 

To  set  the  valves  of  a  locomotive,  the  piston  is 
brought  to  the  end  of  its  stroke,  the  valve  is 
placed  over  the  ports  so  as  to  have  the  desired 


88  THE   LOCOMOTIVE    ENGINE. 

lead  or  advance  on  the  piston ;  the  eccentric  roda 
are  then  adjusted  to  such  a  length  as  to  allow 
the  hooks  to  catch  the  pins,  the  valve  retaining 
the  position  previously  given.  The  engine  is 
now  moved  either  forward  or  backward,  as  may 
be  convenient,  until  the  piston  is  brought  to  the 
other  extreme  of  its  stroke;  and  if  the  valve  has 
the  same  advance  on  the  second  port  as  on  the 
first,  it  is  properly  set.  If,  however,  the  lead  is 
more  or  less  than  that  given  to  the  first  port  to 
which  the  valve  was  set,  the  eccentrics  require  to 
be  turned  in  the  proper  direction  on  the  axle, 
and  to  such  an  extent  as  to  give  the  desired  lead. 
Before  turning  the  eccentrics,  the  eccentric  rod 
must  be  lengthened  or  shortened,  as  the  case  may 
require,  so  as  to  divide  the  difference  of  lead  on 
the  two  ports,  in  order  that  it  may  be  equal  on 
each.  A  proper  adjustment  of  the  length  of  the 
rods  makes  the  lead  equal  on  each  extreme  of  the 
stroke,  while  the  position  given  to  the  eccentrics 
determines  the  amount  of  lead. 

The  eccentrics  may  be  properly  fixed  to  the 
crank  axle,  when  it  is  detached  from  the  wheels 
and  from  the  engine. 

Find  the  point  a  on  the  side  of  the  axle,  and  in 


THE   LOCOMOTIVE   ENGINE. 


89 


Fig.  3. 


the  horizontal  line  A  B,  connecting  the  centres 
of  the  crank.  Then  take  a  piece  of  tin  or  sheet 
iron  and  describe  on  it  the  circle  a  m  n  p,  of  the 
size  of  the  axle;  from  the  same  centre  describe 
a  circle  equal  to  the  throw  of  the  valve.  Then, 
if  the  valve  has  an  indirect  attachment,  as  in 
case  of  the  rocker  shaft,  lay  off  on  the  cylinder 
side  of  the  axle,  the  crank  being  turned  that  way, 
a  distance  Jc  I  equal  to  the  sum  of  the  lap  and 
lead  at  one  end  of  the  valve ;  draw  c  d  through 

8» 


90  THE   LOCOMOTIVE   ENGINE. 

the  point  &,  and  perpendicular  to  the  line  A  B. 
Through  the  points  e  and/,  where  this  line  inter- 
sects the  circle  described  by  the  throw  of  the 
eccentric,  draw  the  diagonal  lines  I  t  and  I  s, 
passing  through  the  points  e  and  /  and  the  centre 
of  the  axle.  The  points  ef  and  /',  at  which  these 
diagonals  intersect  the  circumference  of  the  axle, 
may  be  transferred  by  the  compasses  to  the  axle 
from  the  point  a,  already  found  on  its  side.  The 
extremity  of  the  line  dividing  the  forward  eccen- 
tric in  two  equal  parts,  will  fall  on  er,  and  the 
line  dividing  the  backward  eccentric  will  fall  on 
/',  as  will  be  seen  by  the  diagram. 

In  setting  valves  with  direct  attachment,  the 
distance  k  I  is  applied  to  the  other  side  of  the 
centre  of  the  axle,  and  the  diagonal  lines  tend 
the  other  way. 

We  have  already  explained  the  nature  of  lead, 
and  we  should  perhaps  have  explained  the  term 
lap  before  entering  upon  the  foregoing  instruc- 
tions for  setting  valves.  When  the  valve  is  in 
the  middle  of  its  travel  or  motion  on  the  face  of 
the  cylinder,  the  distance  which  it  laps  at  each 
end  over  the  induction  ports,  is  called  the  lap  of 
the  valve.  The  effect  of  this  lap  is  to  shut  off 


THE   LOCOMOTIVE   ENGINE.  91 

the  steam  before  the  piston  has  completed  its 
stroke,  and  the  lap  valve  thus  acts  as  an  expan- 
sion valve,  to  a  greater  or  less  extent  as  the  lap 
is  more  or  less  considerable.  Indeed,  the  main 
difficulty  in  the  use  of  a  lap  valve  for  a  cut-off  is 
that  of  starting,  especially  with  a  heavy  load  or 
on  a  bad  grade.  Engines  having  no  separate 
cut-off  valves  usually  have  as  much  lap  to  the 
valves  as  will  admit  the  steam  to  the  cylinders 
without  serious  difficulty  in  starting.  The  effect 
of  combined  lead  and  lap,  when  restricted  within 
proper  limits,  is  to  augment  the  speed  of  the 
engine;  the  lead,  by  assisting  the  change  in  the 
motion  of  the  piston  so  as  to  lose  no  time,  and 
the  lap  to  act  as  a  cut-off  valve,  to  derive  the 
benefits  resulting  from  an  expansion  of  the  steam. 
These  benefits,  as  we  shall  hereafter  demonstrate, 
consist  in  being  able  to  do  more  work  with  the 
same  steam,  from  which  result  a  considerable 
economy  in  fuel,  and  a  diminution  in  the  water 
carried  in  the  boiler. 

The  pumps  of  an  engine  are  either  attached 
directly  to  the  cross-head,  and  have  the  same 
stroke  as  the  piston,  or  they  are  worked  by  the 
same  through  a  lever  proportioned  sc  as  to  give 


92  THE   LOCOMOTIVE    ENGINE. 

the  pump  plunger  one-half  or  one-third  the  stroke 
of  the  piston.  Many  recent  engines,  however, 
including  Hinkley's  patterns,  have  an  arm  at- 
tached to  the  outside  crank  pin,  which  communi- 
cates motion  to  the  hind  pair  of  drivers,  the  end 
of  this  arm  being  brought  up  to  within  3|  inches 
from  the  centre  of  the  wheel,  and  working  the 
pump  plunger,  giving  it  a  stroke  of  7J  inches. 
The  pumps,  when  this  connection  is  used,  are 
placed  at  the  hind  end  of  the  outside  framing, 
and  beneath  the  footboard.  The  feed  water  en- 
ters the  boiler  on  the  side  of  the  fire-box  at  a 
point  about  as  high  as  the  lower  row  of  tubes 
Some  contend  that  the  feed  water  should  be 
injected  at  the  bottom  of  the  water  space  about 
the  fire-box,  or  at  the  smoke-box  end  of  the 
boiler,  in  order  that  the  cooling  effects  of  the 
water  may  not  act  directly  upon  the  tube  sheets, 
and,  by  alternately  contracting  and  expanding 
them,  cause  the  tubes  to  leak. 

Pumps  having  one-half  or  one-third  stroke  are 
generally  better  for  engines  running  quick,  than 
full  stroke  pumps,  as  the  barrel  of  the  pump  is 
more  sure  to  fill,  while  the  wear  of  the  valves  is 
not  so  perceptible. 


THE    LOCOMOTIVE    ENGINE.  93 

The  pumps  on  all  recent  engines  are  provided 
with  air  vessels  of  iron  or  brass.  The  form  of 
cup  valve  working  in  a  brass  cage,  used  by 
Souther,  appears  to  us  the  simplest  form  of 
valve  which  can  be  devised.  It  requires  much 
less  fitting  than  any  other  form  of  valve  which 
we  remember  to  have  seen. 

The  joints  between  the  pump  and  the  suction 
and  air  chambers,  and  the  joint  in  the  check 
valve  chamber,  are  usually  ground  joints  of  cast 
iron.  These,  however,  when  long  in  use,  fre- 
quently become  leaky,  as  a  cast  iron  joint  about 
a  pump,  or  in  any  place  where  the  water  has 
access  to  it,  is  found  not  to  hold  its  face  well. 
If  a  composition  ring  be  placed  inside  the  valve 
chamber,  to  make  a  joint  upon,  the  iron  with 
which  it  is  in  contact  becomes  subject  to  a  pecu- 
liar oxidation,  arising  from  a  kind  of  galvanic 
action  with  the  composition  ring.  The  iron  about 
this  ring  often  becomes  eat  full  of  small  holes. 
To  remedy  this  evil,  the  pumps  of  Souther's  en- 
gines have  rings  of  a  composition  cast  inside  the 
valve  chambers,  and  in  every  situation  about  the 
pump  where  a  ground  joint  is  required.  These 
rings  are  first  cast  by  themselves,  and  their  com- 


94  THE    LOCOMOTIVE   ENGINE. 

position  is  so*  proportioned  that  when  placed  in 
the  mould  of  the  valve  chambers,  and  having  the 
melted  iron  poured  around  them,  the  iron  just 
melts  the  surface  of  the  ring,  and  thereby  be- 
comes firmly  cast  with  it,  so  that  water,  which  is 
necessary  for  the  galvanic  action  described,  can- 
not enter  between  them.  We  regard  this  as  a 
very  excellent  plan,  as  it  saves  much  expense  in 
keeping  the  pumps  in  order,  and  makes  no  mate- 
rial difference  in  the  first  cost  of  the  pump. 

The  keys  to  tighten  the  bearings  about  an  en- 
gine should  not  have  too  much  taper,  as  there  is 
danger  of  their  becoming  set  so  tight  as  to  cause 
the  melting  of  the  Babbitt  lining  of  the  boxes. 
When  much  tapered,  they  are  also  liable  to  work 
out,  but  this  does  not  prevent  them  from  being 
set  so  tight  as  to  create  the  mischief  referred  to. 
All  the  bolts  should  be  turned  and  fitted,  and  for 
such  as  pass  through  the  straps  of  the  connecting 
rods,  and  other  parts  in  motion,  check  nuts  are 
required.  The  thread  of  the  screws  should  not 
be  too  coarse,  as  in  that  case  the  nuts  are  apt  to 
work  off;  while  if  too  fine,  the  thread  is  liable  to 
strip.  A  thread  of  eleven  to  the  inch  appears  to 
answer  very  well  for  the  medium-sized  bolts. 


THE   LOCOMOTIVE   ENGINE.  95 

Such  rubbing  surfaces  about  an  engine  as  are 
liable  to  become  rapidly  worn,  require  a  lining 
of  the  composition  usually  named  Babbitt  metal, 
from  the  inventor,  Mr.  Isaac  Babbitt,  of  Boston. 
A  space  is  left  around  the  inside  of  the  shell  of 
the  bearing,  which  is  filled  with  this  composition, 
there  being  ledges  around  the  sides  of  the  shell 
to  keep  the  soft  metal  from  coming  out.  A  com- 
mon proportion  for  the  ingredients  of  this  compo- 
sition is  twenty  parts  tin,  two  of  antimony,  and 
one  of  copper. 

There  should  always  be  oil  cups  on  the  cross- 
heads,  and  means  must  be  found  to  oil  every  rub- 
bing surface  about  the  engine. 

There  should  be  a  little  chance  for  end  play  on 
the  pins  for  the  connecting  rod  to  connect  the 
drivers,  and  also  on  the  pins  for  the  pump  rod. 
This  play  on  the  connecting  rod  may  amount  to  J 
inch,  and  is  necessary  to  allow  the  wheels  to  ride 
freely  around  a  curve. 


We  shall  have  occasion  to  mention  two  or  three 
particular  patterns  of  engines,  and  in  so  doing 
shall  notice  some  peculiar  arrangements  in  the 


96  THE   LOCOMOTIVE    ENGINE. 

various  parts  of  their  moving  machinery,  differing 
from  what  we  have  described.  A  disposition  is 
constantly  shown  among  makers  for  improve- 
ments, and  new  applications  possessing  their 
peculiar  advantages  and  disadvantages  are  con- 
stantly appearing.  Our  most  recent  engines  pos- 
sess many  decided  improvements  over  those  con- 
structed but  a  very  few  years  ago. 


SECTION  VII. 

REMARKS   ON  TH^  MANAGEMENT   OF   ENGINES. 

A  WELL-BUILT  engine,  having  its  parts  easily 
accessible,  and  possessing  good  qualities  for  the 
production  of  steam,  may,  with -careful  manage- 
ment, be  made  to  run  for  a  long  time  with  but 
little  expense  for  repairs.  The  points  to  which 
the  careful  engineman  directs  his  attention  are 
the  manner  of  firing,  the  supply  of  feed  water, 
the  proper  adaptation  of  the  production  of  steam 
to  the  features  of  the  road,  and  various  other 
particulars  of  a  like  nature,  which  are  necessary 
for  the  proper  performance  of  a  locomotive.  It 
is,  of  course,  necessary  to  fire  up  oftener  when 
the  engine  is  performing  hard  work  than  when 
the  load  is  light.  The  fire  should  be  maintained 
at  a  proper  point  to  make  sufficient  steam,  and 
should  not  be  suffered  to  get  so  low  as  to  affect 
the  pressure  in  the  boiler.  It  is  an  object,  how- 
ever, in  approaching  a  terminal  station,  to  have 

9  97 


98  THE    LOCOMOTIVE   ENGINE. 

barely  sufficient  fire  to  reach  the  engine  house. 
The  supply  of  feed  water  to  the  boiler  is  regu- 
lated very  much  by  local  circumstances  on  the 
road.  In  ascending  grades,  the  injection  of  cold 
water  would  check  the  formation  of  steam,  and  it 
is  therefore  necessary  to  have  a  good  supply  of 
water  in  the  boiler  before  reaching  the  foot  of  an 
unfavourable  grade.  On  long  levels  and  on  de- 
scending grades,  one  pump  may  be  kept  working 
to  nearly  its  full  extent.  It  is  seldom  that  both 
pumps  require  to  be  at  work  at  the  same  time. 
There  should  also  be  plenty  of  water  in  the  boiler 
before  reaching  either  roadside  or  terminal  sta- 
tions. The  fire  door  should  be  kept  open  as 
little  as  possible,  as  the  entrance  of  the  cold  air 
through  it  contracts  the  tube  sheets,  and  is  some- 
times the  cause  of  their  leaking. 

If  an  engine  has  a  variable  exhaust,  it  is  a 
good  plan  to  open  it  to  nearly  its  full  extent, 
when  firing,  and  to  immediately  contract  it  very 
much,  so  as  to  recover  the  fire  quickly.  The 
cylinders  and  valves  require  to  be  oiled  at  every 
fifteen  or  twenty  miles  of  the  journey.  Melted 
tallow  is  used  for  this  purpose.  If  the  ports  of 
the  throttle  valve  are  of  the  same  area  as  the 


THE   LOCOMOTIVE    ENGINE.  99 

steam  pipe,  it  is  found  best  to  keep  the  throttle 
partly  closed,  as  when  the  pressure  in  the  steam 
is  rather  less  than  in  the  boilers  the  engine  is  not 
so  liable  to  prime.  The  proper  opening  for  the 
throttle  of  any  engine  can  soon  be  determined 
from  observation. 

In  going  through  covered  bridges  and  station 
houses,  enginemen  are  generally  cautioned  to 
shut  their  dampers,  and  to  otherwise  check  the 
draft  of  their  engines,  so  as  to  guard  against 
fire. 

The  boiler  requires  to  be  blown  off  at  intervals 
of  a  week  or  more.  The  times  at  which  this 
operation  should  be  performed  will  depend  very 
much  on  the  purity  of  the  water  used.  When  a 
scale  deposits  on  the  tubes,  and  on  the  internal 
shell  of  the  boiler,  a  double  handful  of  mahogany 
sawdust  thrown  in  at  the  safety  valve  will  tend 
to  remove  it. 

There  should  be  as  few  putty  joints  about  an 
engine  as  possible ;  but  where  there  are  any 
joints  requiring  packing,  putty  seems  to  answer 
better  than  India-rubber.  It  should  be  mixed  to 
have  a  very  firm  and  even  consistency,  which  end 
is  best  attained  by  mixing  the  red  and  white 


100  THE    LOCOMOTIVE    ENGINE. 

lead  of  which  it  is  composed  by  beating  with  a 
heavy  hand-hammer. 

The  hemp  for  packing  the  piston  rods,  valve 
stems,  and  pump  plungers,  should  be  soaked  in 
warm  water  before  using.  Some  engineers  soak 
it  in  melted  tallow,  but  this  appears  to  rot  it. 
Hemp  simply  soaked  in  warm  water  will  be  found 
strong  after  two  months'  use.  Good  hemp  is  to 
be  preferred  to  India-rubber  for  stuffing  boxes. 

The  frequent  use  of  the  sand-box  on  freight 
engines  has  the  effect  of  rapidly  wearing  out  the 
tires  of  the  wheels.  Its  use  should  therefore 
be  restricted  to  cases  where  it  cannot  be  dis- 
pensed with. 

In  repainting  the  wood  work  about  an  engine, 
the  best  way  of  cleaning  the  work  from  grease 
and  dirt  is  to  wet  it  wTith  spirits  of  turpentine  on 
a  handful  of  waste.  The  steam  chimneys  are 
best  polished  with  rotten-stone,  used  with  oil  on 
a  woollen  cloth. 

Every  engineman  should  know  whether  the 
spring  balances  of  his  safety  valves  are  correctly 
marked.  To  test  the  balances  themselves,  they 
can  be  attached  to  a  balance  known  to  be  correct, 
and  if  the  weight  indicated  on  each  balance  is  the 


THE   LOCOMOTIVE   ENGINE.  101 

*/,  the  spring  of  your  engine  balance  is  cor- 
rect. If  you  wish  to  find  whether  the  spring 
balance  is  correctly  marked, — say,  for  instance, 
to  a  pressure  of  90  Ibs.  to  the  inch, — find  in  the 
first  place  the  diameter  of  the  valve  seat,  or 
smallest  diameter  of  the  valve,  and  find  its  cor- 
responding area  in  square  inches.  Multiply  this 
area  by  90,  and  you  have  the  entire  pressure 
against  the  whole  valve.  Now  from  this'  pressure 
deduct  the  weight  of  the  safety-valve  lever,  with 
the  spring  balance  attached  and  disconnected 
from  the  boiler,  the  lever  being  weighed  at  a 
point  directly  over  the  centre  of  the  safety  valve. 
What  remains  is  the  pressure  against  the  valve, 
which  is  to  be  overcome  by  the  tension  of  the 
spring  balance,  unaided  by  its  weight.  Multiply 
this  pressure  by  the  distance  in  inches  from  the 
centre  of  the  joint  pin  or  fulcrum  to  the  centre 
of  the  valve  pin,  and  divide  the  product  by  the 
distance  from  the  joint  pin  to  the  centre  of  the 
spring  balance.  This  quotient  shows  the  tension 
of  the  spring  balance  requisite  to  overcome  a 
pressure  of  90  Ibs.  per  square  inch  against  the 
valve.  Suppose  this  quotient  to  be  81,  for  in- 
stance ;  then,  in  re-marking  the  spring  balance, 

9* 


102  THE   LOCOMOTIVE   ENGINE. 

the  point  showing  90  Ibs.  per  inch  should  be  at 
81,  as  originally  marked  by  the  maker  of  the 
spring  balance  on  his  scale.  If  the  original 
marks  of  the  spring  balance  have  been  covered 
or  destroyed,  then  attach  a  weight  equal  to  the 
quotient  found  in  the  above  calculation,  and  the 
point  to  which  it  draws  down  the  gauge  or  pointer 
may  be  marked,  and  calculated  from  as  though  it 
were  the  original  mark. 

If  the  balance  be  screwed  down  to  any  point 
supposed  to  show  a  certain  pressure  in  the  boiler, 
a  pair  of  steelyards  can  be  applied  to  the  end  of 
the  safety-valve  lever,  when  the  spring  balance  is 
screwed  to  that  pressure  and  is  attached  to  the 
boiler,  and  the  resistance  or  tension  of  the  ba- 
lance, or  the  weight  sufficient  to  just  raise  it, 
may  be  noted.  This  weight  may  be  multiplied 
by  the  distance  from  the  joint  pin  to  the  balance, 
and  the  product  divided  by  the  distance  from  the 
joint  pin  to  the  centre  of  the  valve  ;  the  quotient 
will  be  the  pressure  against  the  valve,  which  if 
divided  by  the  number  of  square  inches  in  the 
area  of  the  valve,  will  show  the  pressure  per 
inch.  This  method,  it  will  be  seen,  gives  the 
true  result  also  without  deducting  the  weight  of 


THE   LOCOMOTIVE   ENGINE.  103 

the  lever  in  the  calculation,  as  its  weight  is  in- 
cluded in  getting  the  tension  of  the  spring 
balance. 

No  careful  engineman  puts  out  his  fires  by 
throwing  water  in  the  fire-box,  except  in  cases 
demanding  the  immediate  withdrawal  of  the  fire. 
It  is  even  then  better  to  pull  out  the  grate  bars 
by  a  dart,  which  can  be  'done  if  the  fire-box  be 
not  full  of  wood,  as  the  injury  caused  by  contract- 
ing the  tube  sheets  is  irreparable.  To  reverse 
the  steam  also  when  the  engine  is  in  motion 
brings  a  very  powerful  strain  upon  its  bearings. 
It  should  never  be  done,  except  to  prevent  col- 
lision or  running  off  the  t?ack.  When,  to  pre- 
vent a  collision,  it  sometimes  becomes  necessary, 
however,  to  reverse  full  steam  ahead  to  full  steam 
back,  a  difficulty  is  sometimes  found  in  catching 
the  hooks.  The  hand  hooks,  too,  when  dropped 
on  the  pins,  do  not  immediately  catch,  until  they 
will  suddenly  become  engaged  and  put  the  hand 
levers  in  rapid  motion,  so  as  to  become  a  source 
of  danger  to  the  engineman.  It  is  best,  there- 
fore, in  reversing  in  such  cases,  to  place  the  re- 
versing lever  first  midway,  with  all  the  eccentric 
hooks  out,  when  the  hand  hooks  may  be  at  once 


104  THE   LOCOMOTIVE   ENGINE. 

caught  and  the  back  hooks  immediately  thrown 
in.  We  know  old  engineers  who  say  they  always 
do  this  in  cases  of  the  most  imminent  danger; 
and  on  the  whole  it  generally  takes  less  time. 
Where  an  engine  has  V-hooks,  or  links,  there  is 
never  any  difficulty  in  reversing  at  once. 

In  removing  and  replacing  the  steam-chest  and 
cylinder  covers,  care  should  be  taken  that  no  one 
screw  which  secures  them  shall  be  up  to  a  tight 
bearing  when  the  others  are  loose.  In  putting 
them  on,  the  nuts  should  be  turned  loosely  up  all 
around,  and  then  gradually  tightened.  Unless 
these  precautions  are  observed  there  is  danger 
of  cracking  the  covers. 

There  are  very  few  roads  where  any  account  is 
kept  of  the  work  performed  by  their  locomotives, 
so  as  to  show  the  comparative  power  of  each 
engine  on  the  road.  Every  new  engine  is,  to  a 
certain  extent,  an  experiment,  and  its  perform- 
ance will  very  much  depend  on  some  of  the 
details  observed  in  its  construction.  An  engine- 
man  knowing  the  features  of  the  road  over  which 
he  runs — as  the  radii  of  the  curves,  length  and 
height  of  grades,  &c. — may  keep  a  very  useful 
and  interesting  abstract  of  the  load  drawn,  or 


THE   LOCOMOTIVE    ENGINE.  105 

speed  attained,  together  with  the  consumption 
of  fuel,  oil,  &c.,  on  some  of  the  trips  performed 
by  the  machine  in  his  charge.  These  particulars 
are  practically  useful,  inasmuch  as  they  show 
what  may  be  expected  of  a  locomotive  under 
ordinary  circumstances ;  and  they  also  facilitate 
comparisons  of  the  different  patterns  of  engines. 
Some  of  the  roads  running  out  of  Boston  keep  a 
monthly  list  posted  in  their  engine  houses,  of  the 
number  of  miles  run  by  each  of  their  engines, 
together  with  the  amount  of  oil  and  waste  used 
for  the  same  time. 

The  following  is  an  estimate  which  has  been 
furnished  us  of  the  expenses  for  running  a  first- 
class  passenger  engine,  100  miles  a  day  for  one 
year : — 

Wages  of  Engineman $720.00 

"     "    Fireman 360.00 

Wood  ;  4  cords  per  day,  280  days,  ")  ^  040  00 
1120  cords  @  $4.50  per  cord      /  " 

Oil;  280  gallons,  @  .80 224.00 

Waste;  840  Ibs.     ".02 16.80 

Repairs;'  28,000  miles,  @  .06 1,680.00 

Water  in  Boston 100.00 

Water  and  pumping  on  road 150.00 

Interest  on  first  cost  of  engine 480.00 


Total $8.770.80 


106  THE   LOCOMOTIVE    ENGINE. 

This,  though  but  an  approximation,  serves  to 
show  pretty  nearly  the  general  expense  of  loco- 
motive power. 

In  our  railroad  reports  generally,  no  mention 
is  made  of  the  details  of  the  expenditures  on 
account  of  the  locomotive  department ;  and  while 
the  entire  success  of  the  road  depends  upon  the 
condition  of  this  branch  of  its  fixture,  the  sub- 
ject is  passed  without  the  least  notice.  Those 
interested  in  railroad  matters  may  regard  the 
locomotive  of  the  present  day  as  practically 
perfect ;  this,  however,  would  be  a  serious  error, 
and  would  very  much  retard  the  introduction 
of  beneficial  improvements.  On  some  of  the 
Southern  roads — the  Baltimore  and  Ohio,  for 
instance — a  detailed  account  is  appended  to  the 
superintendent's  yearly  report,  containing  the 
number,  names,  rank,  classes,  and  builders  of 
all  the  engines  on  the  road ;  their  performances 
for  the  preceding  year  in  miles  run,  expense 
for  repairs  on  each  engine,  together  with 
details  of  the  charges  for  fuel,  wages,  oil, 
waste,  and  incidental  expenses  connected  there- 
with. 


THE   LOCOMOTIVE    ENGINE.  107 

The  Baltimore  and  Ohio  Railroad*  is  one  of 
the  largest  enterprises  of  the  kind  in  the  country. 
Its  entire  length  from  Baltimore  to  Cumberland, 
including  the  branch  to  the  City  of  Washington, 
is  220  miles;  and  there  are  by  the  last  returns 
sixty-three  locomotives  on  the  road.  The  careful 
attention  paid  to  the  minutiae  of  the  running  de- 
partment on  that  road  presents  a  model  which 
our  engineers  might  well  follow. 

*  This  Company  are  now  extending  their  road  to  Wheeling, 
making  the  entire  road,  when  finished,  431  miles  long.  The 
difficult  passage  over  the  Alleghany  Mountains  will  present 
some  of  the  boldest  and  most  striking  works  of  art  to  be  seen 
in  this  country.  The  new  tunnel  to  pass  through  the  moun- 
tain ridge  will  be  one  mile  and  one  quarter  long.  Several 
iron  bridges  of  180  feet  span;  also  stone  masonry  bridges  of 
that  span  will  be  erected  to  carry  the  line  across  the  nume- 
rous mountain  streams.  This  extension  will  greatly  increase 
the  already  immense  traffic  now  finding  its  channel  in  the 
Baltimore  and  Ohio  Road. 


SECTION  VIII, 

VARIOUS  PATTERNS  OF  LOCOMOTIVES. 

THE  most  recent  patterns  of  passenger  engines 
have  15-inch  inside  cylinders,  four  5-feet  or  5 
J-feet  drivers,  and  a  truck  frame.  This  general 
arrangement  is  seldom  modified  to  any  material 
extent,  although  the  diameter  of  cylinder  is  made 
by  Norris  13  inches,  and  in  some  instances,  by 
other  makers,  16  inches.  The  use  of  two  pairs 
of  drivers  is  necessary  to  obtain  sufficient  adhe- 
sion to  the  rails,  although  an  engine  having  but 
one  pair  of  drivers  runs  much  easier,  and  is  to  be 
preferred  for  special  trains  of  a  few  cars,  and 
running  only  for  short  distances  over  a  nearly 
level  track. 

For  freight  transportation  the  cylinder  is  gene- 
rally 16  to  18  inches  in  diameter,  and  the  driving 
wheels  from  42  to  54  inches  in  diameter.  Hink- 
ley  and  Norris  have  each  patterns  of  ten-wheel 
engines,  with  six  drivers  connected,  and  Winans's 
freight  engines  have  eight  wheels  connected  and 
supporting  the  entire  weight  of  the  engine. 

108 


THE   LOCOMOTIVE   ENGINE.  109 

\Vithin  a  year  or  two  there  have  been  con- 
structed several  engines  in  various  parts  of  the 
country,  of  novel  and  peculiar  design.  The 
chief  feature,  however,  in  these  engines  has  been 
an  increase  in  the  size  of  the  driving  wheels. 
Among  these  engines  was  one  built  by  Edward  S. 
Norris,  of  Schenectady,  N.  Y.,  for  the  Utica 
and  Schenectady  Railroad,  of  the  following  di- 
mensions : 

Sixteen-inch  cylinder,  22-inch  stroke ;  boiler 
42  inches  in  diameter  ;  116  two-inch  tubes,  10  ft. 
3  in.  long ;  grate  about  14  square  feet ;  one  pair 
of  wrought  iron  driving  wheels  behind  the  fire- 
box, and  7  feet  in  diameter;  one  pair  of  wrought 
iron  bearing  wheels  just  forward  of  the  fire-box, 
and  4  feet  in  diameter,  and  a  truck  frame  be- 
neath the  smoke-box  of  four  3J-feet  wrought  iron 
wheels.  The  cylinders  are  outside,  and  are 
placed  in  a  horizontal  position  midway  between 
the  fire  and  smoke  boxes.  A  large  dome,  at  a 
corresponding  point  on  the  top  of  the  boiler, 
supplies  steam  to  the  cylinders  through  pipes 
running  down  outside  the  boiler  to  the  steam 
chests.  The  valve  motion  is  the  modified  form 

of  Stephenson's  link  motion,  on  which  we  have 
10 


110  THE   LOCOMOTIVE    ENGINE. 

remarked  on  a  preceding  page.  The  fra^me  of 
the  engine  is  below  the  axle  of  the  driving 
wheels,  and  above  that  of  the  4-feet  bearing 
wheels,  the  jaws  for  the  bearings  of  the  driving 
axle  being  formed  on  the  upper  side  of  the 
frame.  There  is  also  an  outside  frame  having 
a  floating  bearing  for  the  end  of  the  driving 
axle,  the  crank  and  eccentrics  being  between  this 
bearing  and  the  wheel. 

The  performance  of  this  engine  is  represented 
as  being  remarkably  good. 

The  coal-burning  engine  built  by  Ross  Winans, 
of  Baltimore,  and  placed  by  him  for  trial  on  the 
Boston  and  Maine  Railroad,  had  17-inch  outside 
cylinders  laid  horizontally,  22-inch  stroke,  and 
eight  drivers,  having  chilled  rims  43  inches  in 
diameter,  all  the  drivers  being  placed  between 
the  fire  and  smoke  boxes.  The  connecting  rod 
is  applied  to  the  third  pair  of  wheels  from  the 
smoke-box.  The  distance  between  the  centres 
of  the  extreme  axle  is  11  ft.  3  in. ;  between  the 
centres  of  the  cylinders,  6  ft.  5  in.  The  boiler 
shell  is  made  of  T6ff  iron,  and  measures,  in  its 
smallest  inside  diameter,  41  inches.  There  are 
101  two-and-one-half-inch,  and  2  two-inch  wrought 


THE   LOCOMOTIVE    ENGINE.  Ill 

iron  tubes,  13  feet  in  length.  The  upper  row  of 
tubes  is  nearly  up  to  the  top  of  the  cylinder  part 
of  the  boiler,  the  water-level  being  in  the  dome 
above  the  waist  of  the  boiler.  The  dome  is 
formed  a  little  forward  of  the  middle  point  of 
the  boiler,  having  the  same  diameter,  and  rising 
51  inches  above  it.  There  is  a  tetep  on  the  back 
side  of  the  fire-box,  making  the  length  of  the 
grate  14  inches  more  than  the  length  of  the 
crown  sheet.  The  fire  box  is  of  f-inch  copper, 
with  the  exception  of  the  tube  sheet,  which  is  of 
J-inch  iron.  Length  of  grate,  56J  in. ;  at  crown 
sheet,  42}  in. ;  mean  breadth  of  grate,  42}  in.  ; 
at  centre  of  boiler  or  middle  row  of  tubes,  39} 
in. ;  all  inside  measures.  The  whole  depth  from 
the  crown  sheet  to  grate  is  51}  inches.  The 
grate  bars  are  very  heavy,  and  are  cast  but  two 
together.  Their  ends  come  through  the  bottom 
of  the  fire-box,  on  the  back  side,  and  have  round 
holes  through  which  to  put  a  bar  to  stir  them 
occasionally,  in  order  to  loosen  the  cinders  and 
melted  coal.  The  exhaust  from  both  cylinders 
comes  through  a  cast  iron  box  or  blast  pipe 
having  movable  sides,  so  that  the  aperture  at  its 
mouth  may  be  varied  from  3J-  to  10  square 


112  THE    LOCOMOTIVE    ENGINE. 

inches.  There  is  a  pipe  about  9  inches  in  di- 
ameter, passing  up  through  the  smoke-box,  from 
the  bottom  to  the  top,  and  entering  the  chimney, 
leaving  a  few  inches  all  around  it  for  the  smoke 
to  rise  through.  The  exhaust  enters  this  pipe  at 
its  bottom,  and  the  partial  vacuum  created  by  its 
action  supplies  the  blast,  as  in  ordinary  locomo- 
tives. The  tube  surface  of  this  engine  is  860 
square  feet ;  of  heating  surface  in  fire-box,  66 
square  feet ;  and  the  area  of  grate  is  16 J  square 
feet. 

Messrs.  Slade  and  Currier,  civil  engineers, 
were  commissioned  to  make  experiments  with 
this  engine,  in  order  to  institute  a  comparison 
between  it  and  a  first-class  wood  engine,  but 
more  particularly  to  test  its  actual  value  as  a 
coal-burning  engine.  The  results  of  their  ex- 
periments have  been  published,  but  they  neglect 
to  state  that  the  "  New  Hampshire"  (the  wood 
engine)  was  of  a  materially  different  pattern 
from  the  « coaler,"  inasmuch  as  it  had  six 
driving  wheels  and  a  truck  frame,  thereby 
losing  a  considerable  per  cent,  of  the  adhesion 
due  to  its  weight,  as  compared  with  the  «  coaler." 
The  dimensions  of  the  "New  Hampshire"  were 


THE    LOCOMOTIVE    ENGINE.  113 

as  follows  : — 16-inch  cylinder,  20-inch  stroke  ; 
diameter  of  drivers,  46  inches ;  length  of  tubes, 
10  ft.  6  in. ;  diameter  of  boilerj  45  inches.  This 
engine  was  built  by  Hinkley  &  Drury. 

The  experimental  trips  were  made  in  the 
latter  part  of  January  and  in  the  beginning 
of  February,  1850.  The  entire  distance  from 
Boston  to  Great  Falls  is  given  as  74  miles. 
There  was  more  or  less  snow  on  the  track 
during  the  time  in  which  the  experiments  were 
made.  The  highest  grades  were  about  47  feet 
per  mile.  One  point  unfavourable  for  the 
« coaler"  was  the  fact  that  from  there  being 
but  about  26  miles  of  double  track,  the  freight 
trains  were  subject  to  frequent  and  protracted 
delays,  in  waiting  for  passenger  trains  to  pass. 
In  waiting,  the  fire  in  the  wood  engine  could  be 
suffered  to  go  nearly  down,  the  fire-box  being 
filled  with  wood  when  the  train  came  in  sight. 
In  the  coal  engine,  however,  it  was  necessary 
to  keep  the  furnace  filled  with  coal,  as,  if  suffered 
to  get  down,  it  would  take  considerable  time  to 
recover  the  fire. 

With  the  "  coaler,"  the  average  of  ten  trips 

showed   a   consumption   of  4786  Ibs.  anthracite 
10* 


114  THE   LOCOMOTIVE    ENGINE. 

coal  to  evaporate  3512  gallons  in  going  74 
miles;  this  being  .10.31  Ibs.  coal  required  to 
evaporate  one  cubic  foot  of  water. 

With  the  wood  engine,  3  cords  and  T%  of  a 
foot  of  wood  of  various  qualities  and  prices 
were  used  to  evaporate  3734  gallons  of  water. 

The  cost  of  carrying  15000  tons  one  mile  with 
wood  was  found  to  be $14.04 

With  coal 12.70 

Favour  of  coal $1.34 

The  wood  engine  had  a  sand-box,  and  wrought 
iron  tires;  the  "coaler"  had  a  sand-box  also, 
but  had  chilled  wheels. 

The  "coaler"  took  76  cars,  weighing,  with 
freight,  433  tons,  up  Ward  Hill,  in  Bradford, 
where  there  is  a  grade  of  47  feet  per  mile,  arid 
also  a  very  bad  reversed  curve.  In  going  up  the 
hill  no  sand  was  used,  nor  did  the  wrheels  slip, 
except,  as  the  report  states,  some  three  or  four 
turns  where  some  track  repairers  had  taken  off 
a  hand  car  and  left  a  little  snow  on  the  rails. 

The  wood  engine  took  61  cars  up  the  same 
hill,  weighing,  with  freight,  391  tons.  Sand  was 
constantly  running  from  the  sand-box,  except 


THE   LOCOMOTIVE   ENGINE.  115 

when,  to  ascertain  whether  the  engine  was  work- 
ing up  to  its  full  power,  the  sand  was  turned  off, 
when  the  wheels  were  found  to  slip  very  much. 

The  average  cost  of  wood  used  on  the  through 
trips  was  $3.63  per  cord. 

The  cost  of  anthracite  coal,  per  ton  of  2240 
pounds,  was  $5.25 ;  f  of  a  ton  of  coal  was  found 
to  be  equal  in  effect  for  evaporation  to  one  cord 
of  wood,  or  $3.28  worth  of  coal  equal  to  $3.63 
worth  of  wood. 

The  average  speed  of  the  "  coaler,"  although 
having  a  smaller  wheel  and  a  longer  stroke,  was 
found  to  be  T2o  of  a  mile  per  hour  greater  than 
that  of  the  wood  engine ;  their  average  speeds 
being  14T3jj  and  14T1U  miles  per  hour,  respectively. 
This  was  probably  owing  to  a  loss  on  the  wood 
engine  by  slipping  the  wheels. 

In  conclusion,  the  commissioners  express  their 
opinion  that,  for  running  heavy  trains,  which  are 
not  obliged  to  wait  for  any  considerable  length  of 
time  along  the  line  for  other  trains  to  pass,  they 
believe  coal  to  be  every  way  more  economical 
than  wood.  They  also  say  that  in  their  re- 
marks they  would  not  wish  to  be  considered  as 
in  any  way  disparaging  the  "New  Hamp- 


116  THE    LOCOMOTIVE   ENGINE. 

shire,"  as  they  consider  that  a  first-class  wood 
engine. 

Winans  has  an  express  engine  on  the  Worces- 
ter road,  having  7-feet  drivers.  In  this  engine, 
however,  the  proportions  of  the  boiler,  &c.  are 
very  much  the  same  as  in  the  freight  engine  we 
have  noticed.  These  seven-feet  drivers  were 
cast  with  chilled  rims,  and  were  of  an  extremely 
light  pattern ;  in  fact,  they  became  broken  before 
they  had  been  used  two  months.  There  were  two 
small  steam  cylinders  placed  on  the  sides  of  the 
boiler  over  the  bearings  of  the  driving  axle,  by 
which  the  weight  on  the  drivers  could  be  varied 
from  three  to  twelve  and  a  half  tons.  But  when 
under  their  utmost  adhesion,  the  drivers  were 
found  to  slip  very  much. 

Many  attempts  have  been  made  to  burn  an- 
thracite coal  effectually  and  economically.  Wi- 
nans's  engines  appear  the  best  adapted  for  the 
use  of  this  kind  of  fuel  of  any  yet  constructed. 
We  regard,  however,  a  very  large  extent  of  grate 
with  a  moderate  depth  of  coal  as  still  more  likely 
to  attain  to  superior  results.  For  a  17-inch 
cylinder,  let  the  grate  be  6  feet  by  3J  feet,  the 
depth  of  fire-box  being  3  feet,  and  having  two  or 


THE   LOCOMOTIVE    ENGINE.  117 

three  water  bridges  4  inches  in  thickness  tra- 
versing its  entire  length.  We  are  of  opinion 
that  anthracite  might  be  burned  in  such  a  fire- 
box with  increased  effect  in  the  production  of 
steam,  and  with  a  diminished  waste  in  the  metal 
of  the  fire-box  and  grate  bars.  With  such  a 
furnace,  a  pair  of  small  wheels  would  be  neces- 
sary to  support  the  hind  end  of  it. 

The  difficulties  encountered  in  the  use  of  hard 
coal  arise  chiefly  from  the  intense  and  concen- 
trated heat  involved  in  its  combustion,  thereby 
destroying  the  grate  bars  and  scaling  the  inside 
of  the  fire-box.  This  rapid  burning  out  of  the 
grate  has  led  to  leaving  off  the  ash  pan  on  the 
coal  engines  on  some  of  the  Pennsylvania  roads, 
which  appears  to  remove  to  some  extent  the 
destructive  results  attending  the  use  of  the  coal. 
The  ashes  and  cinders  falling  upon  the  track, 
if  they  do  not  immediately  cause  a  fire, — which 
must  be  guarded  against,— soon  form  an  im- 
penetrable crust  along  the  entire  line,  which 
removes  all  further  danger  from  that  source. 
This,  though  it  may  appear  somewhat  improbable 
at  the  first  view,  accords  with  the  experience  of 
the  roads  where  it  has  been  tried.  Much  diffi 


118  THE    LOCOMOTIVE    ENGINE. 

culty  has  been  met  in  the  use  of  copper  tubes, 
as  the  action  of  the  coal,  from  being  projected  in 
small  pieces  by  the  blast,  was  found  to  cut  them 
away  near  their  mouths.  This  difficulty  sug- 
gested the  use  of  wrought  iron  tubes,  which, 
however,  require  much  caution  in  setting  them, 
as  the  increased  force  necessary  to  head  up 
their  ends  is  apt  to  spring  or  bend  the  tube 
sheet.  A  method  has  been  practised  with  much 
Buccess  on  the  Pennsylvania  roads,  which  is  to 
turn  off  an  inch  or  more  of  the  end  of  the 
wrought  iron  tube  in  the  form  of  the  frustum 
of  a  cone,  thereby  reducing  its  thickness  one 
half  at  its  extreme  end.  The  tube  is  then  placed 
through  the  tube  sjieet,  and  a  thin  thimble  of 
copper,  an  inch  in  length,  and  previously  turned 
off  in  the  same  manner  as  the  tubes,  is  driven 
into  the  mouth  of  the  tube,  with  its  sharpest 
edge  foremost.  After  being  driven  as  far  as  it 
will  go,  the  thick  edge  projecting  outward  is 
turned  over  and  headed  in  the  usual  manner. 

The  creation  of  sufficient  blast  by  the  action 
of  the  exhaust  steam  has  also  been  attended 
with  some  difficulty.  Anthracite  requires  for 
its  proper  combustion  a  very  steady  and  quite 


THE    LOCOMOTIVE   ENGINE.  119 

powerful  blast,  which  the  intermittent  and  fitful 
action  of  the  blast  pipe  of  a  locomotive  fails  of 
producing.  It  has  been  attempted  by  many  ar- 
rangements, however,  to  render  this  kind  of  blast 
regular,  and  capable  of  giving  the  required  in- 
tensity to  the  fire. 

The  pipe  described  as  passing  up  through  the 
smoke-box  of  Winans's  engine,  has  this  result 
for  its  object.  Although  the  steam  enters  the 
bottom  of  this  pipe  by  sudden  and  violent  im- 
pulses, the  pipe  must  be  filled  with  steam,  which 
will  iaeue  in  a  very  regular  manner  from  the  top 
of  it,  where  its  action  is  first  employed  in  causing 
a  draft  through  the  tubes.  It  has  also  been  tried 
to  obtain  a  regular  blast  by  letting  the  exhaust 
steam  into  a  receiver  or  box  a  foot  in  diameter 
and  a  foot  high,  this  box  being  in  the  middle  of 
the  smoke-box.  Eighteen  one-inch  tubes  in  the 
top  of  this  box  afforded  exit  for  the  steam.  This 
plan,  however,  from  the  resistance  caused  by  the 
steam  on  the  reverse  side  of  the  piston  (being 
solicited  to  escape  through  so  difficult  a  passage) 
has  rendered  its  operation  inefficient. 

If  future  experience  determines  the  exhaust 
steam  to  be  insufficient  to  give  a  proper  blast 


120  THE   LOCOMOTIVE   ENGINE. 

for  burning  anthracite,  it  will  become  necessary 
to  adopt  some  of  the  varieties  of  bituminous 
coals,  or  a  mixture  of  anthracite  and  bituminous 
coal.  We  think,  however,  the  exhaust  steam  will 
be  found  sufficient  for  burning  the  former,  under 
ordinary  circumstances,  with  a  large  extent  of 
fire-box  surface. 

We  will  now  notice  a  few  other  patterns  of  en- 
gines from  which  our  remarks  on  burning  coal 
have  arrested  our  attention. 

The  "John  Stevens,"  by  Norris,  Brothers,  of 
Philadelphia,  had  13-inch  cylinders,  34-inch 
stroke,  and  one  pair  of  eight-feet  drivers.  This 
engine  was  intended  to  burn  coal.  Its  operation, 
however,  was  not  attended  with  the  anticipated 
results. 

0.  W.  Bayley,  of  the  Amoskeag  Machine  Shop, 
at  Manchester,  N.  H.,  has  lately  built  an  engine 
with  15-inch  cylinders,  24-inch  stroke,  and  two 
pairs  of  seven-feet  drivers.  There  were  two  stout 
shafts,  resting  in  bearings  beneath  the  frame,  and 
between  the  cylinders  and  driving  axle.  Each 
of  these  shafts  had  two  stout  arms  keyed  to  it, 
the  one  in  a  line  with  the  piston  rod,  to  which  its 
upper  extremity  was  attached  by  a  link;  the 


THE   LOCOMOTIVE   ENGINE.  121 

other  outside  the  frame,  and  which,  by  the  con- 
necting rod  attached  to  it,  communicated  motion 
to  the  driving  wheels.  The  use  of  this  arrange- 
ment was  to  obtain  the  supposed  advantages  of 
inside  cylinders  with  an  outside  connection.  If 
the  proposed  object  was  to  reduce  the  height  of 
the  boiler  from  the  rails  by  avoiding  the  use  of 
the  crank  axle,  we  think  it  might  have  been 
better  attained  through  the  use  of  outside 
cylinders,  placed  midway  on  the  boiler,  and 
connected  to  the  hind  pair  of  drivers.  It  could 
not  be  supposed  that  the  use  of  inside  cylinders 
would  contribute  to  give  the  engine  a  steady 
motion  on  the  road,  so  long  as  the  power  was 
applied  outside  the  wheels.  Had  the  cylinders 
been  placed  as  near  as  they  could  set  to  the 
forward  pair  of  wheels  and  clear  them,  it  would 
have  been  merely  necessary  to  let  the  valve 
stems  enter  the  steam  chests  on  the  front  side. 

Gr.  S.  Griggs  has  lately  finished  an  engine  for 
the  Providence  road,  of  the  following  general 
particulars  : — 14f -inch  cylinders ;  18-inch  stroke ; 
about  a  44-inch  boiler ;  9J-feet  tubes ;  six  driving 
wheels,  supporting  the  entire  weight  of  the  en- 
gine, and  being  48  inches  in  diameter.  These 
n 


122  THE   LOCOMOTIVE   ENGINE. 

wheels  had  chilled  rims,  and  were  all  cast  with 
flanges.  One  pair  of  wheels  was  behind  the 
fire-box,  and  the  connecting  rod  was  applied 
to  the  middle  pair  of  wheels.  From  the  centre 
of  the  hind  pair  of  wheels  to  the  centre  of  the 
middle  pair,  was  5  feet  3  inches;  from  the 
centre  of  the  middle  pair  to  the  centre  of  the 
front  pair,  was  6  feet  9  inches ;  making  the 
entire  distance  between  the  extreme  axles  12 
feet.  There  was  perhaps  |  inch  end  play  on 
the  axle  of  the  back  pair  of  wheels,  none  to 
the  middle,  or  crank  axle,  and  about  J  inch 
in  the  front  axle.  The  engine  had  inside 
cylinders,  inclined  so  as  to  allow  the  cross- 
heads  to  clear  the  forward  axle.  There  was 
an  equalizing  bar  between  the  middle  and  hind 
pairs  of  wheels,  and  an  independent  spring  over 
the  forward  pair. 

The  performance  of  this  engine  in  the  trans- 
portation of  freight  is  mentioned  as  extremely 
good;  and  it  is  stated  that  the  engine  travels 
through  a  curve  with  all  the  facility  of  an  engine 
of  the  usual  pattern. 

One  of  Hinkley's  ten  wheelers  on  the  Northern 
road  was  altered  by  taking  out  the  truck  frame 


THE    LOCOMOTIVE    ENGINE.  123 

and  putting  in  another  pair  'of  drivers.  This 
could  be  done  only  by  setting  the  new  drivers 
very  far  forward,  and  by  springing  up  the 
smoke-box  end  of  the  engine,  as  the  cylinders 
in  this  pattern,  though  somewhat  inclined,  were 
not  intended  to  admit  another  pair  of  driving 
wheels.  The  distance  between  the  extreme  axles 
of  this  engine  is  15  ft.  6  in. ;  the  two  middle 
pairs  of  wheels  have  no  flanges,  and  no  end 
play  was  allowed  in  any  of  the  boxes.  The 
engine  is  said  to  draw  a  much  greater  load  than 
when  running  with  the  truck  frame,  and  is  also 
said  to  ride  as  freely  around  a  curve  as  before 
the  alteration  was  made. 

We  have  never  believed  the  use  of  extra  large 
wheels  on  our  narrow  gauge  roads  would  afford 
proper  grounds  for  their  general  introduction. 
The  high  point  at  which  the  power  of  the  steam 
must  be  applied  to  work  a  seven  or  eight  feet 
wheel,  gives  the  engine  greater  leverage  in  its 
action  on  the  rails,  and  consequently  involves  an 
increased  expenditure  for  repairs,  both  on  the 
road  and  on  the  machine.  The  use  of  large 
wheels  presents  a  choice  of  two  bad  arrange- 
ments :  the  boiler,  to  get  an  inside  connection, 


124        THE  LOCOMOTIVE  ENGINE. 

must  set  very  high,  so  as  to  clear  the  cranks ; 
while  the  only  means  of  reducing  the  height  of 
the  boiler  is  to  carry  the  cylinders  outside,  and 
to  subject  the  whole  engine  to  an  injurious  and 
sometimes  dangerous  oscillating  motion,  owing 
to  the  comparatively  wide  distance  between  the 
points  at  which  the  power  is  applied.  Which- 
ever plan  may  be  adopted  is  found  to  possess 
its  disadvantages.  True,  a  pair  of  large  drivers 
may  be  placed  behind  the  fire-box,  but  one  pair 
of  wheels,  and  at  that  point  also,  does  not  give 
the  engine  sufficient  adhesion  to  the  rails. 

On  the  whole,  we  do  not  believe  the  proposed 
advantages  supposed  to  result  from  the  use  of  a 
3-feet  stroke  will  ever  compensate  for  the  inju- 
rious effects  of  outside  cylinders,  with  large 
wheels.  The  present  speed  of  railroad  travelling 
is  as  great  as  can  be  economically  maintained, 
and  any  attempt  to  increase  it  increases  in  a 
higher  ratio  the  expense  of  repairs  and  renewals. 
In  support  of  our  opinion,  we  can  confidently 
assert  that  no  instance  can  be  adduced  of  a 
narrow-gauge  engine,  in  this  country,  having 
a  wheel  larger  than  six  feet,  where  it  has  been 
thoroughly  tested  and  its  use  approved  of.  The 


THE   LOCOMOTIVE   ENGINE.  125 

high  speeds  attained  by  5J-feet  wheels,  with  the 
express  trains  on  the  Worcester  road,  prove 
that  a  very  rapid  rate  of  travelling  may  be 
reached  with  an  ordinary-sized  wheel. 

Although  we  regard  the  only  sure  means  of 
running  quick  to  be  found  in  perfecting  and 
smoothing  our  roads,  reducing  the  grades, 
easing  the  curves,  and  laying  the  road  with 
more  care  for  smoothness  and  stability,  still 
we  do  not  deny  that  a  large  wheel  would  be 
better  for  light  express  trains,  running  chiefly 
to  transmit  important  despatches  ;  we  do  not, 
however,  think  the  use  of  such  engines  would 
be  advisable  in  running  our  regular  and  heavy 
trains. 

There  are  many  roads  where  trains  of  two 
or  three  cars  are  run  by  twenty-two-ton  engines. 
The  injury  sustained  by  the  permanent  way, 
from  the  continued  passage  of  such  unneces- 
sarily heavy  machines,  has  drawn  a  considerable 
degree  of  attention  to  the  subject  by  practical 
railroad  men,  both  in  this  country  and  in  Europe. 
On  the  Eastern  Counties  line,  in  England,  a 
steam  carriage,  having  engine,  tank,  and  car 

on  one  frame, — the  engine  having  8  inch  cylin- 
11* 


126'  THE   LOCOMOTIVE   ENGINE. 

der,  12  inch  stroke,  5  feet  wheel,  and  255 
feet  heating  surface,  and  the  car  capable  of 
seating  84  passengers, — was  placed  upon  a 
branch  road,  and  was  found  to  require  but 
11J  Ibs.  of  coke  per  mile,  against  31J  Ibs.,  the 
average  amount  consumed  by  the  heavy  engines 
before  used.  The  whole  carriage,  in  working 
trim,  weighed  15  tons  7  cwt. ;  and  with  an 
additional  car, — making  accommodation  in  all 
for  150  passengers, — ran  at  an  average  jate 
of  37  miles  per  hour.  The  use  of  this  mode 
of  traffic,  where  admissible,  is  attended  with  a 
great  diminution  in  the  working  expenses,  and 
in  the  repairs  of  the  line  where  it  is  employed. 

To  carry  120  passengers  on  the  present  sys- 
tem, the  weight  of  engine,  22  tons,  tender,  wood 
and  water,  15  tons,  baggage  car,  8  tons,  and  2 
passenger  cars,  20  tons,  must  be  included.  This 
gives  upward  of  1200  Ibs.  dead  weight  to  each 
passenger  carried,  or  a  train  of  75  tons,  at  an 
average  speed  of  30  miles  per  hour. 


SECTION  IX. 

TABLES  AND  CALCULATIONS  RELATIVE  10  THE 
LOCOMOTIVE. 

IT  is  a  very  useful  and  interesting  mental 
exercise  to  calculate  the  power,  capacity,  and 
other  particulars  of  a  locomotive.  By  an  ac- 
quaintance with  the  expressed  values  of  engines, 
deduced  from  natural  principles,  or  being  per- 
haps the  results  of  ^experimental  research,  our 
minds  become  habituated  to  a  better  conception 
of  their  properties.  At  the  same  time,  we  re- 
quire to  have  the  means  of  knowing  the  capa- 
bilities of  any  machine  in  order  to  direct  or 
suggest  any  improvements  in  its  arrangement; 
and  likewise  to  know  that  we  are  in  possession 
of  all  the  capabilities  in  the  engine  which  science 
can  point  out. 

We  therefore  commence  this  section  with  a 
table  which  we  have  computed  for  the  lengths  of 
stroke  and  diameters  of  wheels  of  our  American 
engines,  and  which  is  intended  to  express  the 

127 


128 


THE   LOCOMOTIVE   ENGINE. 


speed  of  the  piston  compared  with  that  of  the 
circumference  of  the  driving  wheel,  the  speed 
of  the  latter  being  taken  as  1.  The  use  of  this 
table  we  shall  immediately  proceed  to  show. 


«  *J 

I'g 

Diameter  of  Drivers. 

hT 

42  in. 

43  in. 

46  in. 

48  in. 

54  in. 

60  in. 

66  in. 

72  in. 

78  in. 

84  in. 

16 

•2425 

•2369 

•2214 

•2122 

•1886 

•1697 

•1543 

•1415 

•1306 

•1213 

18 

•2728 

•2665 

•2491 

•2387 

•2122 

•1910 

•1736 

•1591 

•1469 

•1364 

20 

•3031 

•2961 

•2768 

•2652 

•2358 

•2122 

•1929 

•1768 

•1632 

•1516 

22 

•3335 

•3257 

•3045 

•2918 

•2594 

•2334 

•2122 

•1945 

•1795 

•1668 

24 

•3639 

•3554 

•3321 

•3183 

•2829 

•2546 

•2315 

•2122 

•1959 

•1819 

Now  to  calculate  the  traotive  force  of  a  loco- 
motive, multiply  the  sum  of  the  areas  of  the  two 
pistons  by  the  effective  pressure  per  square  inch, 
the  effective  pressure  being  understood  as  the 
pressure  in  the  boiler  minus  the  pressure  of 
steam  barely  sufficient  to  keep  the  engine  and 
tender  by  themselves  just  in  motion ; — having 
the  product  so  obtained,  multiply  it  still  further 
by  the  decimal  coefficient  corresponding  to  its 
length  of  stroke  and  diameter  of  wheel,  as 
found  in  the  preceding  table:  this  last  product 
expresses  the  tractive  force  of  the  engine,  in 
pounds. 


THE    LOCOMOTIVE    ENGINE.  129 

To  illustrate  the  meaning  of  traction,  we  will 
suppose  a  deep  pit  to  be  sunk  in  the  middle  of  a 
level  track ;  let  a  weight  in  the  bottom  of  the 
pit  have  a  rope  attached  to  it,  the  rope  passing 
over  a  pulley  at  the  mouth  of  the  pit,  and  being 
secured  at  its  other  end  to  the  draw  iron  of  a 
locomotive.  The  weight  which  the  engine  could 
raise  in  this  manner,  entirely  through  the  ad- 
hesion of  its  drivers,  is  equal  to  the  tractive 
force  of  the  engine. 

Example. — What  is  the  tractive  power  of  a 
locomotive  having  17-inch  cylinders,  22-inch 
stroke,  43-inch  wheels,  and  effective  pressure 
80  Ibs.  per  square  inch  ? 

The  area  of  a  17-inch  piston  is  226-98  square 
inches. 

The  area  of  two  cylinders,  therefore,  453-96 
square  inches. 

And    453-96 
80 


36316-80 

•3257  the  coefficient  of  the  given  wheel 
and  stroke. 


11828-38  Ibs.,  the  product,  which   is  the 


130  THE   LOCOMOTIVE   ENGINE. 

traction  of  the  engine.  The  traction  varies, 
however,  according  to  the  weight  of  the  engine, 
for  which  this  calculation  does  not  provide. 

The  resistance  offered  by  the  friction  of  one 
ton  on  a  level  railroad  is  the  same  as  that  of 
drawing  up  through  the  pit  a  weight  of  10 
pounds.*  That  is,  10  Ibs.  weight  attached  to 
a  load  of  one  ton,  and  passing  over  a  pulley 
so  as  to  act  with  it  full  weight  on  the  load, 
would  keep  it  in  motion.  Hence,  to  find  how 
many  tons  the  above  engine  would  draw  on  a 
level,  divide  the  traction  already  found  by  10, 
the  amount  of  traction  necessary  to  overcome 
the  friction  of  one  ton  on  a  level,  and  the 
quotient  is  the  desired  answer. 

Thus  :  10)11828(1182|  tons  drawn  by  the 

17-inch  cylinder  engine  on  a  level. 

Another  rule  for  obtaining  the  traction  of  an 
engine,  and  deduced  from  the  above,  is  to 
multiply  the  effective  pressure  per  square  inch 
by  the  square  of  the  diameter  of  the  cylinder, 
that  product  by  the  length  of  stroke,  and  divide 


*  On  a  smooth  road,  with  cars  in  good  condition,  the  fric- 
tion is  8,  and  sometimes  as  low  as  7  pounds  per  ton. 


THE   LOCOMOTIVE    ENGINE.  131 

the  whole  by  the  diameter  of  the  wheel  in  inches. 
Thus,  the  above  example  would  become — 

289  square  of  17-inch  cylinder. 
80  Ibs.  pressure  of  steam. 

23120 

22  length  of  stroke. 

43)508640(11828  Ibs.,  as  before. 

The  application  of  this  rule,  it  will  be  seen, 
does  not  require  the  use  of  the  table  of  decimal 
coefficients. 

In  going  up  a  grade  there  is  a  certain  ten- 
dency to  roll  down  the  hill,  occasioned  by  the 
force  of  gravity.  A  portion  of  the  tractive 
power  of  the  engine  is  to  be  expended  in  over- 
coming this  tendency  of  gravity,  as  well  as  the 
friction  of  the  load. 

To  obtain  the  gravity,  in  pounds,  of  one  ton 
on  any  grade,  multiply  2240,  the  number  of 
pounds  in  a  ton,  by  the  height  of  the  grade, 
and  divide  the  product  by  the  length  of  the 
grade.  To  obtain  the  gravity  of  one  ton  on 
a  47-feet  grade,  (the  grade  of  Ward  Hill,  in 
Bradford,  Mass.,)  we  multiply  2240  by  47,  the 


132  THE   LOCOMOTIVE   ENGINE. 

height  of  the  grade,  and  divide  the  product  by 
5280,  the  number  of  feet  in  one  mile,  or  the 
length  of  the  grade ;  the  quotient  is  19-9  Ibs., 
which  is  the  gravity  of  one  ton  on  a  grade  of 
that  pitch.  To  this  must  be  added  the  friction 
of  one  ton,  already  given  as  10  Ibs.,  and  the 
whole  tractive  power  of  the  engine  ''s  to  be 
divided  by  their  amount,  thus : 

29.9)11832(395-7  tons,  answer. 

A  simpler  rule,  deduced  from  the  above,  is  to 
multiply  the  height  of  the  grade  per  mile  in 
feet,  by  the  decimal  4242,  which  gives  precisely 
the  same  answer.  Thus  : 

47  X  4242  =  19-9  +  Ibs 

N.  B. — The  weight  of  the  engine  and  tender 
is  not  included  in  the  above  answers. 

The  friction  of  the  engine  and  tender  absorbs 
from  4  to  6  Ibs.  per  square  inch  on  the  piston, 
and  if  the  engine  is  not  in  good  order  it  will  take 
more. 

To  find  the  quantity  of  water  evaporated  by  an 
engine  in  going  a  certain  distance,  we  can  multi- 
ply the  area  of  the  piston  by  the  length  of  the 
stroke,  or  by  that  part  of  the  stroke  into  which 


THE    LOCOMOTIVE    ENGINE.  133 

dense  steam  is  admitted,  where  a  cut-off  is  \\sed ; 
this  gives  the  capacity  of  one  cylinder,  which, 
multiplied  by  four,  gives  the  amount  of  stoam 
used  at  one  revolution.  Then  divide  the  dis- 
tance of  your  journey  by  the  circumference  of 
the  wheel,  and  make  a  discretionary  allowance 
for  slipping;  this  gives  the  number  of  revo- 
lutions made  by  the  drivers  in  going  the  given 
distance,  which,  multiplied  by  the  amount  of 
steam  used  at  one  revolution,  gives  the  entire 
quantity  of  steam  used  in  going  the  entire  dis- 
tance. The  question  now  arises,  what  part  of 
this  steam  is  water;  or  rather,  what  amount 
of  water  was  required  to  generate  this  amount 
or  volume  of  steam  at  the  given  pressure  ?  We 
can  ascertain  this  by  reference  to  the  table  on 
page  21.  Suppose  the  given  pressure  of  steam 
was  110  Ibs.  per  square  inch;  opposite  this 
pressure  in  the  table  is  241,  the  number  of 
cubic  inches  of  steam  generated  under  a  press- 
ure of  110  Ibs.  per  inch  from  one  cubic  inch 
of  water.  Divide,  therefore,  the  whole  amount 
of  steam  of  110  Ibs.  used  in  the  journey  by  241, 
and  you  have  the  amount  of  water  evaporated  to 

generate  that  steam. 

12 


134  THE   LOCOMOTIVE    ENGINE. 

Example. — How  many  gallons  of  water  would 
an  engine  evaporate  in  running  the  distance 
from  Boston  to  Lowell,  26  miles,  the  engine 
being  of  the  following  dimensions : — 15-inch 
cylinder,  18-inch  stroke,  5-feet  wheel,  pressure 
100  Ibs.  per  inch,  and  cutting  off  at  half  stroke  ? 

176-71  area  of  15-inch  piston  in  square  inches. 
9  =  inches    of    stroke   into   which   dense 

steam  is  admitted. 

1590-39  amount  of  steam  used  by  one  cyl.  at  one 
4        stroke. 

6361-56  amount  of  steam  used  at  one  revolution, 

Now  get  the  distance  in  26  miles  by  mul- 
tiplying by  5280,  the  number  of  feet  in  a  mile, 
thus : — 

5280 
26 

15-708)137280(8739  revolutions  in  go- 
ing 26  miles,  the  divisor,  15-708,  being  the 
circumference  of  the  driver  in  feet  and  deci- 
mals. 

The  number  of  revolutions,  8739,  being  mul- 
tiplied by  the  quantity  of  steam  used  at  one 


THE   LOCOMOTIVE    ENGINE.  135 

revolution,  6361-5  cubic  inches,  the  product  is 
55593148  cubic  inches  of  steam  used  in  going 
26  miles.  Now  the  pressure  is  100  Ibs. ;  and  by 
the  table  on  page  21,  one  cubic  inch  of  water 
makes  260  cubic  inches  of  steam  of  that  press- 
ure. Now  the  whole  quantity  of  steam  used, 
divided  by  260,  gives  the  quantity  of  water 
evaporated  to  generate  that  steam,  which  is,  we 
find  by  dividing,  213819  cubic  inches ;  and  this 
amount,  divided  by  231,  the  number  of  cubic 
inches  in  a  wine  gallon,  gives  925-6  gallons  used, 
which  corresponds  very  nearly  with  the  actual 
quantity  used  by  an  engine  of  the  given  di- 
mensions, and  running  on  the  Lowell  road. 
It  will  be  seen  we  have  made  no  allowances 
for  slipping,  nor  for  any  loss  of  steam  by  blow- 
ing off. 

We  sometimes  wish  to  know  the  amount  of 
advantage  gained  by  using  steam  expansively; 
that  is,  the  advantage  gained  by  cutting  off 
steam  at  any  fraction  of  the  stroke.  Suppose 
the  induction  port  to  a  cylinder  to  remain  open 
during  one  stroke  of  the  piston,  thereby  ad- 
mitting steam  enough  to  fill  the  entire  capacity 
of  the  cylinder,  and  of  the  same  pressure  as 


136  THE    LOCOMOTIVE   ENGINE. 

within  the  boiler.  We  will  then  suppose  the 
amount  of  work  done  or  load  raised  by  that 
engine  to  be  represented  by  the  number  3. 
Take  then  the  same  cylinder,  place  the  piston  at 
the  end  of  the  stroke,  and  admit  steam  by  the 
valve  until  the  piston  has  gone  through  one-third 
the  distance  of  the  stroke.  Now  the  load  raised 
by  the  engine  is  either  the  same  load  as  when 
full  steam  was  used,  but  to  only  one-third  the 
distance,  or  one-third  of  the  former  load  to  the 
same  distance.  In  either  case,  the  work  done  is 
represented  by  one-third  the  number  used  to 
represent  the  former  load ;  and  that  number 
being  3,  the  work  done  when  the  piston  has  gone 
through  one-third  of  its  stroke  is  1.  But  when 
the  piston  is  at  that  point  of  its  stroke,  one-third 
of  the  length  of  the  cylinder  is  filled  with  steam 
of  the  same  pressure  as  in  the  boiler  ;  this  steam 
therefore  acts  upon  the  piston,  at  first  with  its 
full  pressure,  but  as  the  piston  moves  along, 
thereby  increasing  the  capacity  of  that  end  of 
the  cylinder,  the  steam  expands  and  presses 
with  a  diminished  force,  until  the  piston  has 
arrived  at  the  extreme  of  its  stroke ;  when  the 
steam  which  was  admitted  until  the  piston  was  at 


THE    LOCOMOTIVE   ENGINE.  13T 

one-third  stroke  has  now  become  expanded  into 
three  times  its  original  volume,  and  thereby  has 
only  one-third  of  its  original  pressure  remaining. 
But  it  has  pressed  upon  the  piston  with  a  con- 
stantly diminishing  force  during  the  last  two- 
thirds  of  the  stroke,  and  has  thereby  contributed 
to  the  useful  effect  of  the  engine.  The  steam 
originally  admitted,  after  performing  an  amount 
of  work  represented  by  the  number  1,  has  per- 
formed during  the  last  two-thirds  of  the  stroke  a 
still  further  amount  of  work,  which  in  reality 
should  be  represented  by  a  number  a  trifle  over 
1,  making  the  entire  useful  effect  derived  from 
one-third  of  a  cylinder  full  of  steam,  a  trifle 
more  than  two-thirds  of  what  it  was  when  a  full 
cylinder  of  steam  was  used.  It  is  evident  that 
none  of  this  additional  useful  effect,  derived 
from  the  expansive  property  of  steam,  could 
have  been  obtained  had  steam  of  full  pressure 
been  constantly  admitted  upon  the  piston 
throughout  its  whole  stroke.  Were  there  suffi- 
cient steam  in  a  boiler  to  fill  a  given  cylinder 
12  times  full,  the  pressure  in  the  cylinder 
being  the  same  as  in  the  boiler,  and  the  work 
performed  by  using  this  steam  through  the  whole 

12* 


138  THE   LOCOMOTIVE   ENGINE. 

stroke  of  the  piston  to  be  represented  by  12,  it 
follows  that  by  filling  only  one-third  of  the 
length  of  the  cylinder  at  each  stroke,  there 
would  be  sufficient  steam  for  36  strokes,  the 
the  effect  of  each  being  represented  by  f ,  and 
of  the  whole,  24,  or  twice  the  effect  obtained  by 
using  the  steam  at  full  stroke.  And  thus  it 
appears  that  although  you  .  can  never  obtain  the 
full  effect  of  the  engine  except  with  full  steam, 
still,  more  work  can  be  done  by  expansion, 
when  compared  with  the  amount  of  steam 
used.  Hence,  there  is  a  very  great  economy 
in  employing  full  steam  through  but  a  portion 
of  the  stroke,  letting  the  stroke  be  completed 
by  the  expansion  of  the  steam  already  in  the 
cylinder. 

Again,  this  principle  of  expanding  the  steam 
in  the  .cylinder,  while  it  reduces  the  quantity 
of  steam  used,  has  no  effect  on  the  production 
of  steam  in  the  boiler,  other  than  what  results 
from  throwing  a  surplus  pressure,  as  it  accu- 
mulates, upon  the  water-level.  By  tracing  the 
practical  applications  of  this  advantage,  we  find 
a  given  boiler  may  supply  a  larger  cylinder,  or  a 
given  cylinder  may  be  supplied  by  a  smaller 


THE   LOCOMOTIVE   ENGINE.  139 

boiler,  and  do  more  work  than  with  the  original 
proportions  before  expansion.  With  expansion, 
therefore,  the  same  work  may  be  performed  with 
a  reduction  in  the  weight  of  the  engine,  which 
is  a  very  important  advantage.  The  less  the 
resistance  of  the  load,  the  greater  may  be  the 
extent  to  which  expansion  is  carried  in  the 
cylinder,  and  for  this  reason  expedients  are 
sometimes  resorted  to  for  adapting  the  expansion 
to  the  resistance  of  the  train. 

Having  thus  explained  the  philosophy  which 
dictates  the  use  of  expansion  or  cut-off  valves, 
we  will  give  a  table  by  which  the  effect  of  the 
.  engine  may  be  estimated  for  any  amount  of 
expansion.  This  table  is  called  a  table  of  hyper- 
bolic logarithms ;  and  as  an  explanation  of  the 
manner  in  which  the  table  is  prepared  would 
encroach  upon  our  limits,  and  at  the  same  time 
be  foreign  to  the  character  of  our  work,  we  will 
confine  ourselves  to  the  manner  of  employing 
this  table  for  the  purpose  of  calculating  the 
effect  due  to  the  expansion  of  steam.  We  mil 
first  present  the  table. 


140 


THE   LOCOMOTIVE    ENGINE. 


TABLE    OF   HYPERBOLIC   LOGARITHMS. 


No. 

Hyp. 
Log. 

No. 

Hyp. 
Log. 

No. 

Hyp. 

Log. 

No. 

Hyp. 
Log. 

1-05 

•049 

2-05 

•718 

3-05 

•115 

4-05 

1-399 

1-1 

•095 

2-1 

•742 

3-1 

•131 

4-1 

1-411 

M5 

•140 

2-15 

•765 

3-15 

•147 

4-15 

1-423 

1-2 

•182 

2-2 

•788 

3-2 

•163 

4-2 

1-435 

1-25 

•223 

2-25 

•811 

3-25 

•179 

4-25 

1-447 

1-3 

•262 

2-3 

•833 

3-3 

1-194 

4-3 

1-459 

1-35 

•300 

2-35 

•854 

3-35 

1-209 

4-35 

1-470 

14 

•336 

2-4 

•875 

3-4 

1-224 

4-4 

1-482 

1-45 

•372 

2-45 

•896 

3-45 

1-238 

4-45 

1-493 

1-5 

•405 

2-5 

•916 

3-5 

1-253 

4-5 

1-504 

1-55 

•438 

2-55 

•936 

3-55 

1-267 

4-55 

•515 

1-6 

•470 

2-6 

•956 

3-6 

1-281 

4-6 

•526 

1-65 

•500 

2-65 

•975 

3-65 

1-295 

4-65 

•537 

•7 

•531 

2-7 

•993 

3-7 

1-308 

4-7 

•548 

•75 

•660 

2-75 

1-012 

3-75 

1-322 

4-75 

•558 

•8 

•588 

2-8 

1-030 

3-8 

1-335 

4-8 

•569 

•85 

•615 

2-85 

1-047 

3-85 

1-348 

4-85 

1-579 

•9 

•642 

2-9 

1-065 

3-9 

1-361 

4-9 

1-589 

•95 

•668 

2-95 

1-082 

3-95 

1-374 

4-95 

1.599 

2 

•693 

3 

1-099 

4 

1-386 

5 

1.609 

To  use  this  table  in  estimating  the  gain  by  ex- 
pansive force : — Divide  the  whole  length  of  the 
stroke  by  the  distance  through  which  the  piston 
travels  before  the  closing  of  the  cut-off  valve ; 
find  in  the  table  the  hyperbolic  logarithm  of  the 
quotient,  add  1  to  it,  and  the  amount  is  the  ratio 
of  uniform  and  expansive  force, 


THE   LOCOMOTIVE   ENGINE.  141 

Example. — Let  the  stroke  of  a  locomotive  be 
18  inches,  and  the  steam  cut  off  at  12  inches ; 
what  is  the  ratio  of  the  gain  ?  18  divided  by  12 
gives  for  the  quotient  1J.  The  hyperbolic  loga- 
rithm corresponding  to  this  number  in  the  table 
is  -405,  (which  we  must  remember  is  decimal;) 
and  adding  unity  to  it,  it  becomes  1405,  the 
effect  by  cutting  off  at  f  stroke  as  compared  with 
1-5  the  effect  when  using  full  steam,  or  -937  of 
the  effect  of  full  steam  by  using  but  f  steam. 

In  getting  the  heating  surface  and  capacity 
of  a  boiler,  we  require  every  extent  of"  surface 
in  the  parts  which  determine  the  shape  and  size 
of  the  boiler,  in  order  to  arrive  at  a  correct 
result.  To  get  the  contents  of  the  water  room 
in  a  boiler,  we  must  first  find  the  diameter  of  the 
boiler  in  inches,  and  find,  by  calculation,  its 
corresponding  sectional  area.  To  obtain  the 
area  of  water  section,  deduct  the  sectional  area 
of  all  the  tubes  from  one-half  the  sectional  area 
of  the  boiler;  then  find  the  average  between  the 
width  of  the  centre  of  the  boiler,  that  is,  ita 
diameter,  and  the  width  of  the  water-level,  and 
multiply  this  average  by  the  depth  of  water 
above  the  centre  of  the  boiler.  This,  added  to 


142  THE   LOCOMOTIVE   ENGINE. 

the  water  section  in  the  lower  half  of  the  boiler, 
gives  the  entire  water  section.  Now,  multiply 
this  by  the  length  of  the  cylindrical  part  of  the 
boiler ;  multiply  the  width,  depth,  and  thickness 
of  the  water  spaces  together ;  make  the  proper 
deduction  in  the  contents  of  the  back  water 
space  for  the  door,  and  in  the  front  water  space 
for  the  tubes,  which  pass  through  it ;  multiply 
the  area  of  the  crown  sheet  by  the  depth  of 
water  on  its  surface,  and  make  the  proper  deduc- 
tion for  the  stay  bars  ;  and  the  entire  contents  in 
cubic  indies,  divided  by  1728  for  cubic  feet,  or 
by  231  for  wine  gallons,  will  give  a  pretty  accu- 
rate result  for  the  capacity  of  the  boiler. 

The  steam  room  of  the  boiler  is  calculated 
very  much  in  the  same  way.  The  steam  section 
in  the  cylindrical  part  of  the  boiler  is  obtained 
by  deducting  the  water  section  and  tube  section 
from  the  boiler's  sectional  area,  this  being  nmU« 
tiplied  by  the  length  of  the  cylindrical  part  of 
the  boiler,  as  for  the  water  content.  As  the 
circle  of  the  outside  fire-box  is  generally  a  little 
larger  than  that  of  the  boiler,  a  separate  calcu- 
lation should  be  made  for  this  part.  The  content 
of  the  dome  must  also  be  found,  and  a  deduction 


THE   LOCOMOTIVE    ENGINE.  143 

made  for  the  steam  pipe.  In  getting  the  extent 
of  heating  surface  on  the  tubes,  we  must  calcu- 
late it  from  the  outer  circumference  of  the 
tubes ;  for,  although  the  fire  is  only  in  contact 
with  their  inner  circumferences,  the  whole  thick- 
ness of  the  tube  becomes  heated,  so  that  the 
outer  circumference  has  the  same  temperature  to 
heat  the  water  as  the  inner  circumference  re- 
ceives from  the  fire.  The  English  engineers 
reckon  the  tube  surface  of  a  locomotive  as  but 
one-third  as  effective  as  the  fire-box  surface ;  so 
that  an  engine  with  54  square  feet  of:  .fire-box 
surface,  and  660  square  feet  of  tube  surface, 
would  be  reckoned  as  having  only  54  plus  220, 
or  274  square  feet  of  heating  surface. 

In  getting  the  fire-box  surface,  we  should 
reckon  every  square  inch  of  heated  surface  in 
contact  with  the  water,  which  would  of  course 
be  the  four  sides  and- the  crown  sheet,  deducting 
only  the  areas  of  the  outsides  of  the  tubes,  and 
the  space  occupied  by  the  door,  and  the  bar 
riveted  around  it.  The  heating  surface  of  the 
fire-box  could  not  be  considered  as  extending 
below  the  grate.  We  have  already  said  that 
the  practice  is  sometimes  to  reckon  only  the 


144  THE    LOCOMOTIVE   ENGINE. 

back,  sides,  and  top  of  the  fire-box  as  heating 
surface,  but  we  should  suppose  that  a  man  having 
woodland,  pasturage,  and  mowing  land,  might 
with  as  much  propriety  give  the  size  of  his 
mowing  fields  for  the  size  of  his  farm. 

The  surface  of  the  grate  is  of  course  simply 
the  length  and  breadth  multiplied  together. 

We  have  already  given  the  manner  of  cal- 
culating the  ratios  of  the  safety-valve  levers, 
on  page  101. 

There  can  properly  be  no  such  expression  as 
the  horse  power  of  a  locomotive.  The  difference 
between  a  stationary  and  a  locomotive  engine  is 
such  that  while  the  former  raises  a  load,  or  over- 
comes any  directly  opposing  resistance,  with  an 
effect  due  to  its  capacity  of  cylinder,  the  load 
of  the  locomotive  is  drawn,  and  its  resistance 
must  be  adapted  to  the  simple  adhesion  of  the 
engine,  and  which  may  be  varied  even  as  the 
rims  of  the  wheels  are  of  wrought  or  cast  iron, 
as  the  rails  are  in  good  or  bad  order,  as  the 
grades  of  the  track,  the  speed  of  the  engine, 
and  various  unsettled  circumstances  which  cannot 
well  be  resolved  so  as  to  give  an  expression  of  the 
power  of  the  locomotive  in  the  term  horses'  power 


THE   LOCOMOTIVE   ENGINE.  145 

Stationary  steam  engines  are  applied  to  a  vast 
variety  of  purposes,  but  locomotives  are  only 
required  for  one  kind  of  work.  A  cotton  manu- 
facturer negotiating  for  a  steam  engine,  would 
not  care  to  know  how  many  feet  of  lumber  were 
sawed,  nor  how  many  bushels  of  grain  were 
ground  by  a  certain  sized  engine;  nor  would  a 
miller  wish  to  know  the  power  of  an  engine  for 
spinning  cotton  or  weaving  cloth.  The  standard 
of  a  horse  power  serves  as  a  standard  of  com- 
parison, and  its  utility  as  a  unit  of  reference  is 
not  impaired  whether  it  represent  the  actual 
power  of  one  horse  or  three,  so  long  as  the 
standard  is  universal.  But  as  the  work  of  a 
locomotive  is  all  of  one  character,  it  becomes 
an  object  to  know  the  actual  power  of  an  engine 
in  drawing  freight  or  passengers,  in  preference  to 
referring  it  to  any  doubtful  standard,  not  ex- 
pressing its  capabilities.  This  we  have  illus- 
trated at  the  commencement  of  this  section ;  but 
for  the  assistance  of  such  as  may  have  occasion 
to  estimate  the  horses'  power  of  a  stationary,  or 
even  a  locomotive  engine,  we  will  give  the  usual 
rule.  It  is  as  follows : — Multiply  the  area  of 
the  piston,  the  pressure  of  steam  per  square 

13 


146  THE  LOCOMOTIVE   ENGINE. 

inch,  the  number  of  revolutions  per  minute,  and 
the  length  of  stroke  together,  divide  the  product 
by  33,000,  and  take  T7V  of  the  quotient  for  the 
effective  horses'  power  of  the  engine. 

It  is  a  received  law  in  mechanical  science,  that 
the  effect  of  a  machine  is  to  be  estimated  from  its 
weight  or  elemental  power  multiplied  into  the 
space  through  which  the  power  acts.  Our  read- 
ers will  detect  that  in  the  above  rule  we  have 
directions  to  employ  but  one-half  the  speed  of 
the  piston  to  get  the  power  of  the  engine.  For 
instance,  a  16-inch  cylinder  engine  is  usually 
rated  as  a  50-horse  engine ;  but  if  in  calculating 
its  power  we  employ  the  actual  speed  of  the 
piston  in  feet  per  minute,  we  shall  find  our 
engine  to  have  100  horses'  power. 

If  a  horse  raise  150  Ibs.  through  220  feet  in  a 
minute,  or,  through  the  application  of  wheels  and 
axles,  levers,  &c.,  he  raises  33,000  Ibs.  one  foot 
high  in  a  minute,  then  what  is  usually  termed  a 
one-horse  engine  will  raise  66,000  Ibs.  through 
the  same  distance  and  in  the  same.  time.  We 
have  always  supposed  that  the  reason  for  taking 
but  one-half  of  the  speed  of  the  piston  in  es- 
timating the  power  of  an  engine,  arose  from  the 


THE   LOCOMOTIVE   ENGINE.  147 

fact  that  the  steam  engine  was  employed  on  its 
first  introduction  in  pumping  water  from  mines, 
and  for  raising  water  for  towns,  where  only  one 
stroke  of  the  engine  was  effectual.  A  horse 
may  raise  a  constant  load  of  33,000  Ibs.  one  foot 
per  minute,  but  in  pumping  he  could  raise  but 
half  that  sum,  for  one-half  of  his  time  would  be 
expended  in  driving  the  piston  of  the  pump 
downward.  Hence,  though  our  present  allow- 
ance for  a  horse's  power  answers  every  purpose 
for  a  standard  of  reference  to  determine  merely 
the  comparative  power  of  engines,  still  we  shall 
contend  that  our  usual  manner  of  getting  the 
power  of  an  engine  gives  us  but  one-half  the 
proper  amount  of  its  capabilities. 

We  will  give  an  example  illustrating  the  rule 
we  have  given  for  estimating  the  horses'  power  of 
a  steam  engine. 

What  is  the  horses'  power  of  an  engine  having 
a  14-inch  cylinder,  42-inch  stroke,  the  pressure 
of  steam  being  71  Ibs.  per  square  inch,  and  the 
fly-wheel  making  37  revolutions  per  minute  ? 
N.  B. — The  speed  of  the  piston  to  be  obtained  in 
the  usual  manner,  by  multiplying  the  number  of 
revolutions  into  the  length  of  stroke. 


148  THE   LOCOMOTIVE   ENGINE. 

153-94  sq.  in.  area  of  a  14-inch  piston. 
71  Ibs.  per  square  inch. 


10929-74  Ibs.  entire  pressure  on  the  piston. 

Now  we  wish  to  ascertain  the  number  of  feet 
the  piston  travels  per  minute,  or  rather,  half  the 
actual  number : — 

37    number  of  rev.  per  min. 
3J  length  of  stroke  in  feet. 


129-5  speed  of  piston  in  feet  per  min. 

10929-74  pressure  on  piston. 
129-5    speed  of  piston. 


33000)1415401  (42-9  horse  power. 
And  y7^  of  this  quotient  is  30  horses'  power,  the 
power  of  the  engine. 

To  get  the  capacity  of  a  tender  tank,  we  must 
first  obtain  the  extent  of  surface  on  the  bottom 
of  the  tank,  which,  multiplied  by  its  height  or 
depth,  and  reduced  to  gallons,  gives  its  capacity. 
To  illustrate  this  calculation,  we  will  give  a 
diagram  of  Hinkley's  tank  for  a  six-wheeled 
tender. 


THE   LOCOMOTIVE   ENGINE. 


149 


Fig.  4. 

Radius  of  corners  #,  #,  and  a',  a',  6  inches. 
Depth  of  tank,  35  inches. 

The  part  A  may  be  considered  as  an  exact 
parallelogram,  since  the  surface  cut  off  by  the 
corners  a,  #,  is  again  made  up  by  those  at  a',  ar. 
The  sum  of  the  two  semicircular  terminations 
5,  b,  of  the  wings  B,  B,  has  of  course  the  area 
of  one  entire  circle  two  feet  in  diameter ;  and 
these  semicircles  reduce  the  length  of  the 
straight  part  of  the  wings  B,  B,  one  foot. 
Hence,  the  area  of  the  surface  of  the  tank  is 
as  follows : — 


13* 


150  THE   LOCOMOTIVE   ENGINE. 

85  X  66  5610  area  of  part  A. 

66  X  24  X  2       3168     «     «  wings  B,  B. 

452     «     "  terminations  5,  6. 


9230  sq.  in.  surface  of  tank. 
35  depth  of  tank. 

323050  cub.  inches  in  tank.. 

This  last  product,  expressing  the  contents  of 
the  tank  in  cubic  inches,  may  be  divided  by  231, 
and  we  shall  have  the  capacity  of  the  tank  in 
gallons.  This  we  find  to  be  1398J  gallons. 

The  young  machinist  will  readily  perceive 
there  is  no  difficulty  in  making  any  of  these 
calculations,  as  they  involve  only  the  simplest 
rules  of  arithmetic,  while  their  solution  forms  a 
very  useful  and  interesting  mental  exercise.  It 
is  an  excellent  idea  for  any  one  wishing  to  get 
thoroughly  acquainted  with  the  steam  engine, 
to  measure  and  preserve  the  proportions  of  every 
engine  that  may  come  in  his  way ;  these  dimen- 
sions, sooner  or  later,  assume  a  high  value  to  the 
possessor,  inasmuch  as  he  finds  them  convenient 
for  reference  in  comparison,  estimation,  or  in 
designing  new  work.  They  also  serve  to  bring 


THE  LOCOMOTIVE   ENGINE.  151 

him  in  closer  acquaintance  with  the  principles 
of  the  mechanical  science  involved  in  the  theory 
and  the  practical  construction  of  the  steam 
engine. 

To  get  the  area  of  a  circle. — Square  its  di- 
ameter; that  is  to  say,  multiply  the  diameter 
into  itself,  and  multiply  this  product  by  the  deci- 
mal number  -7854 ;  the  last  product  will  be  the 
area  of  the  circle. 

Example  1. — What  is  the  area  of  a  17-inch 
piston  ? 

17 

17 

289 
•7854 

226-98  square  inches  area,  answer. 
Example  2. — What  is  the  sectional  area  of  a 
steam  pipe  4J  inches  inside  diameter  ? 
4-5 
4-5 

20-25 

•7854 

15-904  square  inches  area,  answer. 


152  THE   LOCOMOTIVE   ENGINE. 

N.  B. — In  multiplying  with  decimal  numbers, 
we  must  recollect  to  point  off  as  many  places 
from  the  right  hand  of  the  product  for  deci- 
mals as  there  are  places  of  decimals  in  the 
multiplier  and  multiplicand  taken  together. 

To  get  the  circumference  of  a  circle,  multiply 
the  diameter  by  3-1416;  the  product  is  the 
circumference. 

Another  method  is  to  multiply  the  diameter  by 
355,  and  to  divide  the  product  by  113.  To  those 
accustomed  to  proportion,  this  rule  might  be 
presented  thus : — 

113  :  355  :  :  diameter  :  circumference. 

These  two  numbers  may  be  readily  carried 
in  the  mind  from  a  slight  peculiarity  in  the 
order  of  their  arrangement.  By  setting  the 
two  numbers  down  in  the  following  manner,  it 
will  be  seen  there  are  two  ones,  two  threes,  and 
two  fives,  thus:  113355. 

Examples. — What  is  the  circumference   of  a 
copper  tube  2  inches  in  diameter  ? 
3.1416 
2 

6.2832  inches,  answer. 


THE   LOCOMOTIVE   ENGINE.  Io3 

What  is  the  circumference  of  a  driving  wheel 
66  J  inches  in  diameter  ? 
66-5 
355 


113)23607-5(208-9  in.,  answer. 

N.  B. — In  dividing  with  decimal  numbers,  we 
must  point  off  as  many  places  for  decimals  in  the 
quotient  as,  taken  with  those  in  the  divisor,  if 
any,  will  equal  the  number  of  decimal  places  in 
the  dividend.  Division  is  the  reverse  of  mul- 
tiplication, and  the  divisor  and  quotient  are 
factors,  of  which  the  dividend  is  the  product. 

What  is  the  circumference  of  a  5-feet  driving 
wheel  ?  Five  feet  reduced  to  inches  becomes  60 
inches. 

355 
60 


113)21300(188496  inches,  answer 


154 


THE   LOJOMOTIVE   ENGINE. 


TABLE    OF   THE   AEEAS   OF   PISTONS. 


Diana. 

Area. 

Diam. 

Area. 

10  in. 

78-540 

14*  in. 

165-130 

10* 

86-590 

*14f 

170-873 

11 

95-033 

15 

176-715 

11* 

103-869 

15* 

188-692 

12 

113-097 

16 

201-062 

12* 

122-718 

.  16* 

213-825 

13 

132-732 

17 

226-980 

13* 

143-139 

17* 

240-528 

14 

153-938 

18 

254-469 

TABLE  OF  THE  CIRCUMFERENCES  OF  DRIVERS. 


Diam. 

Circum. 

Diam. 

Circum. 

42  in. 

131  -94  in. 

60  in. 

188-50  in. 

43  « 

135-08  « 

66  " 

207-34  « 

46  " 

144-51  « 

72  " 

226-19  " 

48  « 

150-80  « 

78  « 

245-04  " 

54  " 

169-64  « 

84  " 

263-89  " 

Size  of  Grigg's  cylinders  on  the  Providence  road. 


SECTION  X. 

MISCELLANEOUS  NOTES  AND   OBSERVATIONS. 

THE  principal  locomotive  concerns  in  this  coun- 
try at  the  present  time,  are  the  following : — 

Portland  Locomotive  Works,  Portland,  Maine — 

Horace  Felton  Superintendent. 
Amoskeag  Manufacturing  Co.,  Manchester,  N.  H. 

— Oliver  W.  Bayley,  Superintendent. 
Essex  Company,  at  Lawrence,  Mass. — Caleb  M. 

Marvell,  Superintendent. 
Lowell  Machine  Shop,  at  Lowell,  Mass. — William 

A.  Burke,  Superintendent. 
Boston    Locomotive    Works,    Boston — Hinkley, 

Drury,  and  others,  Proprietors ;   D.  T.  Child, 

Treasurer. 
Union  Works,    South   Boston— Seth  Wilmarth, 

Proprietor. 

Globe  Works,  South  Boston— John  Souther,  Pro- 
prietor. 

155 


156  THE   LOCOMOTIVE   ENGINE. 

Taunton    Locomotive    Manufacturing    Company, 

Taunton,  Mass. — W.W.Fairbanks,  Agent. 
Mattewan  Machine  Works,  Fishkill  Landing,  New 

York — W.  B.  Leonard,  Agent. 
Norris  Locomotive  Works,  Schenectady,  N.  Y. — 

Edward  S.  Norris,  Proprietor. 
Rogers,  Ketchum  &  Grosvenor,  Paterson,  N.  J. 
Swinburn  and  Smith,  Paterson,  N.  J. 
Ross  Winans,  Baltimore,  Md. 
Baldwin  and  Whitney,  Philadelphia,  Pa. 
Norris,  Brothers,  Philadelphia,  Pa. 

Denmead*  at  Baltimore,  a  shop  at  Richmond, 
Va.,  and  an  establishment  at  Cleveland,  Ohio, 
also  advertise  to  build  locomotives. 

In  Boston,  the  Maine,  the  Providence,  and  the 
Worcester  railroads  have  built  many  engines  for 
themselves. 

The  Springfield  Car  and  Engine  Co.,  and  the 
Ballardvale  Machine  Shop  at  Andover,  Mass., 
have  been  nearly  closed ;  and  the  manufacture  of 
locomotives  at  those  places  has  been  entirely  sus- 
pended. 

Jabez  Coney,  of  South  Boston,  built  at  his 
shop,  in  1847,  two  locomotives  for  the  Old 
Colony  road. 


THE    LOCOMOTIVE    ENGINE.  J.77 

The  price  of  a  first  class  21-ton  passenger 
engine,  varies,  according  to  the  style,  from  6800 
to  8000  dollars.  Freight  engines,  from  being 
built  from  heavier  patterns,  generally  cost  more. 

Below  we  give  estimates  of  the  weights  of 
some  of  the  principal  parts  about  a  locomotive, 
and  about  the.  average  prices  usually  charged  for 
such  items. 

42-inch  boiler,  7500  Ibs.,  @  14c $1050.00 

135  If-inch  copper  flues,  10|  feet  long,  2500  Ibs., 

@  30c 750.00 

Turning  and  driving  thimbles,  setting  do.,  &c 30.00 

Solid  engine  frame,  2500  Ibs.,  @  6c 150.00 

Jaws  of  wrought  iron,  1000  Ibs.,  @  lOc 100.00 

Finishing  frame 150.00 

4  driving  wheels,  for  5£  ft.  di.,  6000  Ibs.,  @  3c 180.00 

1  crank  axle,  6£  in.  finish,  1500  Ibs.,  @  18c 270.00 

1  straight  axle,  650  Ibs.,  @  lOc 65.00 

2  truck  axles,  3£  in.  journals,  480  Ibs.,  @  6c 28.80 

4  truck  wheels,  30  in.  diameter 70.00 

4  Lowmoor  tires,  5£  ft.,  2850  Ibs.,  @  13c 370.50 

Finishing  wheels,  cranks,  and  axles 200.00 

2  cylinder  castings,  15  inches  in  diameter,  1600  Ibs., 

@  3c 48.00 

Boring  cylinders 50.00 

2  rough  connecting  rods,  360  Ibs.,  @  8c 28.80 

'JTTo 

The  prices  given  are  perhaps  a  fair  average, 
and  the  whole  table  may  serve  to  show  about 

14 


158  THE   LOCOMOTIVE   ENGINE. 

* 

the  usual  weight   of  the   heavier  and  more  im- 
portant parts  of  a  locomotive. 

In  regard  to  explosions,  we  do  not  believe  any 
well  made  boiler  ever  gave  way  to  do  any  serious 
damage,  except  through  a  want  of  water  in  it. 
If  the  water  is  suffered  to  get  below  the  upper 
row  of  tubes,  the  fire  generally  burns  them  out, 
the  water  rushes  into  the  fire-box  and  extin- 
guishes the  fire,  thus  preventing  all  danger; 
but  enginemen  have  sometimes  found  their  water 
entirely  run  down,  and  the  flues  entirely  spoilt 
by  the  fire,  but  not  burnt  out.  We  recollect — 
and  perhaps  others  who  may  read  this  will  recol- 
lect also — of  an  instance  on  the  Lowell  and  Law- 
rence road  where  an  officer  of  the  road  undertook 
the  management  of  an  engine,  and  succeeded  in 
boiling  every  drop  of  water  away,  burning  the 
wooden  lagging  off  the  boiler,  and  burning  the 
tubes  so  as  to  make  it  necessary  to  replace  every 
one  of  them,  though  they  were  not  burnt  through. 
When  the  water  is  boiled  entirely  away,  and  the 
internal  shell  of  the  boiler  becomes  heated  red 
hot,  the  admission  of  cold  water  generally  pro- 
duces an  explosion.  Some  attribute  this  to  the 
immediate  decomposition  of  the  nitrogen,  one  of 


THE   LOCOMOTIVE   ENGINE.  159 

the  principal  gases  which  enter  into  the  compo- 
sition of  water,  and  leaving  the  hydrogen  to  ex- 
plode by  the  intense  heat.  But  the  presence  of 
oxygen  is  necessary  for  the  explosion  of  hydrogen 
gas  ;  and  a  very  distinguished  chemist  has  averred 
that  there  can  be  no  oxygen  in  a  boiler  filled  with 
steam.  A  recent  theory  is  that  of  the  sphe- 
roidal state  of  water  when  thrown  upon  a  red  hot 
plate.  The  water,  it  is  stated,  when  thrown  upon 
a  plate  heated  to  a  very  high  rate  of  temperature, 
assumes  the  spheroidal  state,  rolling  over  the 
plate  in  smooth  globules,  like  a  mass  of  melted 
lead;  while  in  this  state,  no  steam  can  be  pro- 
duced from  the  water  ;  but  when  the  temperature 
of  the  plate  falls  to  a  certain  extent,  the  water 
becomes  almost  instantaneously  converted  into 
steam  of  intense  and  overwhelming  elasticity, 
and  the  consequence  is,  the  boiler  gives  way  in 
the  weakest  part. 

We  would  not  wish  to  revive  in  this  place  the 
question  of  the  explosion  on  the  Providence  road, 
about  which  there  was  so  much  diversity  of 
opinion ;  but  we  must  say,  that  in  that  instance, 
the  report  of  the  commission,  notwithstand- 
ing its  high  authority,  hardly  succeeded  in 


ICO  THE    LOCOMOTIVE   ENGINE. 

satisfying  the  minds  of  a  large  portion  of  the 
public. 

A  recent  act  of  the  Massachusetts  Legislature 
requires  that  the  boiler  of  every  stationary, 
locomotive,  or  marine  engine,  running  within  the 
State,  shall  have  a  fusible  plug  in  the  crown 
sheet  of  the  furnace.  To  answer  this  require- 
ment, a  lead  plug  J  inch  in  diameter  is  tapped 
into  the  crown  sheet  of  a  locomotive  furnace,  so 
that  when  the  top  of  the  fire-box  becomes  un- 
covered with  water,  this  plug  may  melt,  and  by 
letting  the  steam  escape  into  the  fire-box,  give 
notice  of  the  danger. 

At  the  introduction  of  railroads,  engines  were 
built  with  cylinders  no  larger  than  8  inches  in 
diameter.  In  1840,  we  think  there  were  no  en- 
gines with  cylinders  larger  than  12  inches.  In 
1844,  we  had  13J-inch  cylinders ;  by  1847,  15 
inches ;  and  now,  Perkins,  on  the  Baltimore  and 
Ohio  road,  is  building  an  engine  with  a  20-inch 
cylinder.  The  gauge  of  our  roads  remains  the 
same  now  as  it  was  a  dozen  or  fifteen  years  ago — 
four  feet  eight  and  one-half  inches  inside  the 
rails.  In  those  days,  two  trains  per  day,  drawn 
by  the  light  engines,  were  all  which  the  business 


THE   LOCOMOTIVE   ENGINE.  161 

of  a  road  would  warrant.  Now,  we  have  twenty 
to  thirty  trains  drawn  over  our  principal  roads 
daily,  by  engines  averaging  from  twenty  to 
twenty-five  tons  in  weight.  These  facts  are 
sufficient  to  show  a  vast  increase  of  business 
wherever  railroads  are  extended.  This  constantly 
growing  traffic  must,  at  no  distant  period,  demand 
the  adoption  of  a  wider  gauge  for  our  tracks. 
Railroad  men  prefer  engines  with  inside  cylinders 
to  those  having  the  cylinders  outside.  Every 
engine  requires  apparatus  for  reversing  and  for 
working  expansively ;  and  no  better  means,  we 
think,  have  yet  been  found  to  effect  these  objects 
than  the  use  of  six  eccentrics.  Here  the  in- 
sufficiency of  the  width  of  the  track  becomes 
evident ;  it  is  only  by  economizing  every  inch  of 
room  that  sufficient  space  can  be  found  to  arrange 
the  work  of  an  inside  cylinder  engine.  It  would 
be  a  matter  of  very  great  convenience  were  the 
track  wider  than  at  present ;  and  we  believe  that 
the  experience  of  a  dozen  years,  at  most,  will  de- 
termine it  to  be  a  matter  of  absolute  necessity. 
The  gauge  of  the  Atlantic  and  St.  Lawrence, 
and  the  Androscoggin  and  Kennebec  roads,  in 

Maine,  is  five  feet  six  inches  inside  the  rails,  and 
u* 


162  THE   LOCOMOTIVE   ENGINE. 

that  of  the  New  York  and  Erie  railroad  is  si* 
feet.  Wherever  a  break  of  gauge  is  made,  it 
would  seem  of  importance  that  the  addition  in 
width  should  be  uniform  on  all  roads,  as  a 
difference  in  tracks  disturbs  the  traffic,  inas- 
much as  no  means  exist  of  forwarding  goods 
by  such  roads,  except  by  changing  cars. 

Every  railroad  doing  any  considerable  amount 
of  business,  should  have  sufficient  and  capacious 
repair  shops  of  its  own.  The  increased  facility 
and  convenience  with  which  they  can  do  their 
own  repairs,  and  the  saving  in  the  profits  which 
outside  shops  charge  them,  make  it  a  matter  of 
economy  to  repair  their  own  work.  For  a  rail- 
road having  fifteen  to  twenty  locomotives,  a  shop 
120  by  60  feet,  and  one  story  high,  if  properly 
laid  out,  makes  a  very  convenient  repair  shop. 
For  such  a  shop  there  would  probably  be  required 
for  tools,  &c., 

One  stationary  steam  engine,  (25  horse,)  say $1500 

locomotive  boiler  with  wrought  iron  flues 1800 

large  engine  lathe  to  swing  six  feet 1500 

14  feet  planing  machine 800 

12  feet  engine  lathe,  with  screw  feed 350 

12     "        "        "     without  screw  feed ...  300 


Carried  forward $6250 


THE   LOCOMOTIVE   ENGINE.  163 

Brought  forward $6250 

One  10  feet  engine  lathe,  without  screw  feed 250 

hand  lathe  for  iron 175 

"        "     "  wood 125 

bolt-cutting  machine 250 

wall  drill 125 

suspended  drill  for  tires 125 

machine  for  drawing  on  wheels 50 

blower  for  blacksmith's  shop 50 

forge  hammer 400 

Total  $7800 

We  merely  give  the  above  estimate  to  show 
with  how  few  tools  and  at  how  little  expense  the 
repairing  department  of  a  railroad  may  be  con- 
ducted. In  arranging  such  a  shop,  however,  the 
fancy  or  belief  of  many  would  lead  them  to  have 
many  additional  tools,  such  as  one  16-feet  engine 
lathe,  a  compound  planer,  (the  expense  of  these 
two  being  about  $1000 ;)  and  for  an  increased 
business,  some  would  think  a  spliner  ($500)  and 
some  other  tools  necessary.  We  know,  however, 
of  some  roads  having  twenty  locomotives,  and 
doing  all  their  repairs  with  a  list  of  tools  such  as 
is  comprised  in  our  original  estimate. 

We  give  below  the  particulars  of  the  weight 
and  performance  of  some  of  the  heaviest  engines 
on  the  Fitchburg  road,  from  the  Director's  Report 


164 


THE   LOCOMOTIVE   ENGINE. 


for  1849.  The  whole  number  of  engines  on  the 
road  on  the  31st  of  December,  1849,  was  twenty- 
five. 

N.  B. — The  following  engines  were  built  by 
Hinkley,  with  the  exception  of  the  "Boston," 
which  was  built  by  Lyman  and  Souther,  of 
South  Boston. 


Names. 

i 

Stroke. 

g 
» 

Athol  
Concord  
Shirley 

15  in. 
15 
14 
16 
15 
15 
16 
16 
16 

20  in. 
20 
18 
20 
18 
18 
20 
20 
20 

foi 

si 

ir  4£  ft. 

? 
? 

5 

f 

x  46  in. 

Tru 

ck  out 
ins 

side  cyli 
ide 

nd'r. 

Lincoln  
Cambridge... 
Littleton  
Boston  

Fitchburg.... 
Ontario  

THE   LOCOMOTIVE    ENGINE. 


165 


P  •* 

2. 

11 

1 

1 

f!» 

1 

l| 

1 

.a 

Names. 

|| 

§ 
1 

t|j 

Capacity  of 
Tender. 

§ 

i 

II 

•Si 
« 

pi 

I 

Ibs. 

Ibs. 

Ibs. 

Galls, 
water. 

Cords 
wood. 

Athol    .... 

40,000 

30,000 

27,000 

1,400 

1 

6 

10,419 

Concord.... 

40,000 

30*000 

27',000 

,400 

1 

6 

19^348 

Shirley  

34,000 

24,000 

23,700 

,200 

1 

6 

23,222 

Lincoln  

46,600 

30,900 

29,000 

,600 

11 

8 

19,050 

Cambridge. 

40,000 

28,000 

27,752 

,400 

1 

6 

25,182 

Littleton  ... 

40,000 

28,000 

27,700 

,400 

1 

6 

25,474 

Boston  

46,000 

30,000 

30,000 

,500 

!$• 

8 

29,000 

Fitchburg.. 

46,600 

30,900 

29,000 

1,600 

li 

8 

12,792 

Ontario  

47,000 

36,000 

28,058 

1,600    lj 

8 

9,515 

The  "  Champlain,"  an  engine  of  the  same 
dimensions  as  the  "  Ontario,"  ran  24,628  miles 
in  the  same  time. 

In  regard  to  the  strength  of  boiler  iron  and 
the  effects  of  high  temperatures  upon  it,  it  was 
ascertained  from  experiments  made  by  a  com- 
mittee of  the  Franklin  Institute,  that  at  a  tem- 
perature of  32°,  the  freezing  point,  the  cohesive 
strength  of  boiler  iron  was  4  below  its  maximum, 
and  that  its  strength  increased  as  an  additional 
temperature  was  applied,  until  it  had  reached  570 


166  THE   LOCOMOTIVE    ENGINE. 

degrees  Fahrenheit,  when  the  iron  was  found  to 
have  attained  its  maximum  strength.  Above  this 
point,  the  strength  of  the  iron  was  diminished ; 
at  720°  it  had  the  same  cohesive  strength  as  at 
32°,  or  \  below  its  maximum ;  at  1050°,  one-half 
its  greatest  strength;  at  1240°,  one-third;  and 
at  1317°,  nearly  one-seventh.  Copper  follows  a 
different  law,  as  every  addition  of  temperature 
above  the  freezing  point  appears  to  weaken  it. 
At  529°,  it  has  but  three-fourths  its  greatest 
strength;  at  812°,  but  one-half;  while  a  tem- 
perature of  1300°  entirely  destroys  its  cohesive 
force. 

The  adhesion  of  the  wheels  of  an  engine  is 
about  one-fifth  the  weight  when  the  rails  are 
clean,  and  either  perfectly  wet  or  perfectly  dry, 
but  only  from  one-tenth  to  one-twelfth  the  weight 
when  the  rails  are  damp  or  greasy.  Thus,  for  a 
rough  calculation,  a  25-ton  engine  will  have  5 
tons  adhesion  ;  and  as  the  resistance  of  a  train 
on  a  level  is  about  ^io?  such  an  engine  should 
draw,  including  its  own  weight  and  that  of  its 
tender,  1000  tons  on  a  level.  This  would  be  its 
maximum  load  at  a  slow  speed. 

We  recollect  the  published  report  of  the  per- 


THE   LOCOMOTIVE    ENGINE.  167 

formance  of  one  of  Baldwin's  six-driver  engines 
— the  "  Ontario" — in  1845,  on  the  Philadelphia 
and  Reading  road.  The  train  consisted  of  150 
cars  fully  loaded  with  coal,  the  weight  of  the  coal 
being  759  tons,  and  of  the  coal  and  cars  1180 
tons.  The  engine,  it  was  stated,  moved  along 
alone  with  this  extraordinary  train  at  a  rapid 
rate.  A  four-wheel  engine,  having  its  entire 
weight  on  the  drivers,  drew  from  Lowell  to 
Boston,  in  July,  1849,  a  train  of  one  hundred 
and  twenty-nine  cars,  mostly  loaded.  This  en- 
gine had  13J-inch  cylinders. 


HAVING  completed  the  original  design  of 
our  little  work,  we  here  give  some  particulars  of 
the  present  state  of  the  railway  system,  which 
must  prove  interesting  to  all. 

According  to  the  Railroad  Journal,  there 
were,  at  the  commencement  of  1849,  18,656 
miles  of  finished  railroad  in  the  world,  costing 
.£368,567,000,  or  about  1800  millions  of  dollars; 
also  7829  miles  of  unfinished  road,  which  at  the 
estimate  of  £146,750,000,  would  give,  in  all, 


168  THE   LOCOMOTIVE    ENGltfE. 

26,485  miles  of  railroad,  costing  2400  millions  of 
dollars;  all  of  which  has  been  invested  since 
1830! 

In  July,  1850,  there  were  7742  miles  of  rail- 
road in  the  United  States,  2423  miles  of  which 
are  in  New  England.  Whole  amount  expended 
on  roads  in  operation  since  1834,  $300,000,000. 

At  the  end  of  1848,  there  were  in  Great 
Britain  and  Ireland  5127  miles  opened,  2111 
miles  in  progress,  and  4795  miles  authorized, 
but  not  commenced.  On  4253  miles  opened,  in 
the  United  Kingdom,  on  May  1,  1848,  there 
were  52,688  operatives.  On  7388  miles  of  un- 
opened road,  there  were  188,177  operatives. 
The  total  amount  of  money  and  securities  paid 
into  railroad  treasuries  on  these  lines  to  the 
commencement  of  1849,  was  one  thousand  mil- 
lions of  dollars,  while  the  companies  retained 
power  to  raise  by  existing  shares,  new  shares, 
and  loans,  the  further  sum  of  £143,717,773. 

In  1850,  there*  were  24  roads  in  France,  of 
1722  miles,  and  including  portions  constructing, 
but  not  finished,  2996  miles.  Average  cost  per 
mile,  $128,240. 

In    1849    there    were    2294    miles    of    road 


THE   LOCOMOTIVE   ENGINE.  169 

opened  in  Austria,  Prussia,  and  the  German 
States. 

In  Belgium,  347  miles,  owned  by  government. 

In  Holland,  about  110  miles. 

In  the  north  of  Italy,  there  is  a  line,  partly 
finished,  from  Venice  to  Turin  and  Alexandria. 
When  the  proposed  tunnel  beneath  the  Alps  shall 
be  completed,  this  road  will  form  a  main  link  in 
the  great  direct  railroad  line  from  London  to  the 
Adriatic. 

There  are  short  roads  in  nearly  all  the  States 
of  continental  Europe,  except  in  the  States  of  the 
Church,  where  the  Pope  has  opposed  tkeir  intro- 
duction. And  Russia,  aided  by  American  energy 
and  skill,  is  opening  a  vast  road  between  her  two 
great  capitals,  Moscow  and  St.  Petersburg. 


A  GLOSSARY 

OF   TERMS   APPLIED   TO    THE    MACHINERY,    AND    TO 
THE   OPERATION   OF-  THE   LOCOMOTIVE   ENGINE. 


[N.  B. — Many  of  the  names  and  terms  here  used  are  ex- 
plained at  greater  length  in  the  body  of  the  book.] 


Adhesion. — The  measure  of  the  friction  between  the  tires 
of  the  driving  wheels  and  the  surfaces  of  the  rails.  The 
adhesion  varies  with  the  weight  on  the  drivers  and  the 
state  of  the  rails,'  but  with  a  good  rail  is  generally  from 
one-fifth  to  one-seventh  of  the  weight  on  the  drivers. 
The  load  drawn  is  no  measure  of  the  adhesion,  except 
the  resistance  of  friction  and  gravity  of  the  load  be 
given. 

Air  Chamber. — A  tight  vessel  attached  to  the  pump. 
The  feed  water,  entering  it  at  the  bottom,  is  subjected 
to  the  pressure  of  air  within  it.  which  forces  out  the  water 
in  a  steady  stream.  Recent  engines  have  two  air  cham- 
bers to  each  pump — one  on  the  suction,  and  one  on  the 
forcing  side  of  the  same.  The  capacity  of  air  chamber 
should  equal  that  of  the  barrel  of  the  pump. 

Angle  of  Friction. — That  pitch  of  grade  at  which  a 
loaded  car  would  just  stand  without  descending,  being 
kept  at  rest  by  the  friction  of  its  bearings.  Allowing  tho 

171 


172  GLOSSARY. 

friction  to  be  7  Ibs.  per  ton,  this  grade  would  be  16 1  feet 
per  mile ;  for  10  Ibs.  friction  per  ton,  23  J  feet  per  mile. 

Ash  Pan. — A  box  or  tray  beneath  the  furnace,  to  catch 
the  falling  ashes  and  cinders. 

Axle. — The  revolving  shaft  to  which  the  wheels  are 
secured. 

Blast  Pipes. — Two  pipes,  contracted  at  their  mouths, 
to  discharge  the  waste  steam  from  the  cylinders.  Their 
action  excites  an  artificial  draft  or  blast  in  the  fur- 
nace. ^ 

Blow-off  Cock. — A  cock  at  the  bottom  of  the  fire-box, 
through  which  to  empty  the  boiler. 

Boiler. — The  source  of  power ;  the  vessel  in  which  the 
steam  is  generated. 

Bonnet. — A  wire  cap  or  netting,  surmounting  the  chim- 
ney, to  keep  down  the  sparks  and  cinders. 

Box. — A  bearing,  enclosing  the  journal  of  a  revolving 
shaft.  When  made  in  two  parts,  the  lighter  is  called  the 
cap.  When  made  as  a  single  piece,  and  supporting  the 
end  of  an  upright  shaft,  a  step ;  and  when  turned  outside 
and  fitted  into  a  frame,  or  stand,  a  bushing.  To  reduce 
friction,  boxes  are  lined  with  soft  metal. 

Brake. — A  block  or  strap  applied  to  the  rim  of  a  wheel, 
to  check  its  motion  and  bring  it  to  a  stop. 

Bunters. — Guards  projecting  from  the  ends  of  tendera 
and  cars,  and  connected  with  springs,  to  prevent  shocks 

from  collisions. 
t/^'* 
Cam. — A  plate  or  pulley,  turning  on  a  shaft  out  of  its 

centre.  When  made  round  and  encircled  by  a  strap,  and 
employed  to  work  the  valves  of  a  steam  engine,  and  foi 
similar  purposes,  it  is  called  an  eccentric. 


GLOSSARY.  173 

Case.— A  casting  sliding  in  the  jaw,  and  to  hold  th6 
brass  box  of  an  axle.  For  drivers,  the  case  is  lined  with 
Babbitt  metal,  and  forms  the  bearing  for  the  axle. 

Check  Valve.— See  Valve. 

Counterbalance. — A  large  block  secured  between  .two 
arms  of  each  driving  wheel,  to  balance  the  momentum 
of  the  moving  machinery  connected  with  the  axle. 

Connecting  Rod. — Rod  to  communicate  the  pressure  on 
the  piston  to  the  crank. 

Crank. — In  inside  cylinder  engines  is  forged  in  the  axle, 
and  for  outside  cylinders  is  supplied  by  a  pin  in  the  wheel. 
The  crank  converts  the  rectilineal  motion  of  the  piston  to 
the  rotary  motion  of  the  wheels. 

Cross  Head. — A  block  moving  in  guides ;  having  the 
end  of  the  piston  rod  secured  within  it  at  one  side,  and  a 
pin  to  attach  the  connecting  rod  at  the  other. 

Cut-off  Valve. — An  additional  valve,  not  indispensable, 
to  shut  off  the  admission  of  steam  to  the  cylinder,  when 
the  piston  has  only  completed  a  part  of  its  stroke. 

Cylinder. — A  cylindrical  vessel,  closed  at  its  ends  by 
covers.  Steam  is  admitted  alternately  at  each  end,  to 
press  upon  a  block  called  the  piston.  The  piston  is  made 
to  fit,  steam  tight,  to  the  inner  circumference  of  the  cylin- 
der, and  the  action  of  the  steam  keeps  it  in  motion,  from 
one  end  of  the  cylinder  to  the  other. 

Damper.— A.  door,  to  exclude  the  air  from  the  furnace. 

Dome. — An  elevated  chamber  on  the  top  of  the  boiler, 
from  which  the  steam  is  taken  to  the  cylinders. 

Draw  Iron. — A  rigid  bar,  connecting  the  engine  and 
tender,  and  secured  to  each  by  a  pin. 
Drivers,  or  Driving   Wheels. — Those  wheels  turned  di- 

15* 


174  GLOSSARY. 

rectly  by  the  moving  machinery  of  the  engine,  and 
which,  by  their  adhesion  to  the  rails,  propel  the  engine 
along.  ^ 

Eccentrics. — See  Cam. 

Eduction  Port. — A  passage  on  side  of  cylinder  to  lead 
away  the  waste  steam  from  same,  to  the  blast  pipes. 

Equalizing  Lever. — A  bar  suspended  by  its  centre,  be- 
neath the  frame,  and  connected  at  each  end  to  the  springs 
of  the  drivers,  to  distribute  any  shock  or  jolt  between  both 
pairs  of  wheels. 

Expansion  Valve. — See  Cut-off. 

Fire-box. — The  furnace  of  the  boiler. 

Foaming. — An  artificial  excitement,  or  too  great  ebulli- 
tion on  the  water-level,  observed  when  the  boiler  has 
become  greasy,  or  otherwise  foul.  Generally  productive 
of  priming. 

Footboard. — A  plate  iron  floor,  behind  the  boiler,  for  the 
engineman  and  fireman  to  stand  upon. 

Frame. — Made  to  attach  to  the  boiler,  cylinders,  axles, 
and  all  cross  shafts,  and  binds  the  whole  fabric  together. 

Friction,  of  Trains. — The  friction  of  the  bearings  of  the 
carriages,  and  for  every  ton  drawn,  offers  a  direct  resist- 
ance of  from  seven  to  ten  pounds. 

Frost  Cocks. — Cocks  to  admit  steam  to  the  feed  pipes 
leading  from  the  tender  to  the  pump;  used  when  the 
water  becomes  frozen. 

Gauge  Cocks. — Cocks  at  different  levels  on  the  side  of 
the  fire-box,  and  to  ascertain  the  height  of  water  in  the 
boiler.  When  opened,  water  or  steam  will  escape,  accord- 
ing as  the  level  of  the  water  is  above  or  below  them. 


GLOSSARY.  175 

Gland. — A  bushing  to  secure  the  packing  in  a  stuffing- 
box. 

Grade. — The  inclination  of  a  road ;  expressed  either  by 
the  number  of  feet  rise  per  mile,  or  by  naming  the  dis- 
tance passed  in  rising  one  foot ;  thus,  a  grade  of  1  in  330, 
which  is  16  feet  per  mile. 

Gravity. — The  tendency  which  all  bodies  have  to  find 
the  lowest  level.  The  resistance  in  pounds,  occasioned  by 
the  gravity  of  one  ton  on  any  grade,  may  be  found  by  mul- 
tiplying the  grade,  in  feet  per  mile,  by  the  decimal  number 
•4212. 

Grate. — The  parallel  bars  supporting  the  fuel  in  the 
fire-box. 

Guides. — Rods,  or  bars,  lying  in  the  direction  of  the 
axis  of  the  cylinder,  and  guiding  the  cross  head,  to  insure 
a  perfectly  parallel  motion  in  the  piston  rod. 

Hand  Levers. — Levers  to  work  the  main  valves  by 
hand. 

Housing. — See  Jaw. 

Induction  Ports. — Two  passages  on  side  of  cylinder,  to 
admit  steam  within  it,-^-one  port  communicating  with 
each  end. 

Jaw. — A  stand  secured  to  the  frame,  to  hold  the  box  of 
an  axle.  5he  jaw  must  allow  the  box  to  slide  up  and 
down  within  it. 

Journal. — The  part  of  a  shaft  or  axle  resting  in  the 
box. 

Lagging. — A  wooden  sheathing  around  a  boiler  or 
cylinder. 

•  Lap. — The  distance  which  the  valve  overlaps  on  each 


170  GLOSSARY. 

end  over  the  induction  ports,  when  in  the  middle  of  its 
travel. 

Lead. — Distance  to  which  the  induction  port  is  opened, 
when  the  piston  commences  its  stroke. 

Link  Motion. — An  arrangement  for  working  the  valves, 
described  in  the  body  of  the  book. 

Manometer. — An  instrument  for  determining  accurately 
the  pressure  on  a  given  surface — as  a  square  inch — within 
the  boiler. 

Man  Hole. — A  hole  to  admit  a  man  within  the  boiler. 

Mud  Hole. — A  small  opening  at  bottom  of  water  space 
around  fire-box,  to  clear  out  deposites  of  dirt,  and  other 
matter  introduced  with  the  water. 

Packing. — Any  substance  used  to  make  a  joint  steam  or 
water  tight. 

Pet  Cock. — A  small  cock  between  the  check  valve  and 
pump,  to  see  if  the  latter  is  working. 

Pintal. — An  upright  pin.  There  is  a  pintal  secured 
beneath  the  forward  end  of  the  engine,  to  connect  it  with 
the  truck  frame,  and  to  allow  of  the  turning  of  the  truck, 
independent  of  the  engine. 

Piston. — See  Cylinder. 

Piston  Rod. — Rod  secured  at  one  end  within  the  body 
of  the  piston,  and  at  the  other  to  the  cross  head.  This  rod 
passes  through  the  cylinder  cover,  and  is  made  steam  tight 
by  packing  secured  in  a  necking,  or  recess,  outside  of 
cover,  and  called  a  stuffing-box. 

Plug,  Fusible.— A  lea.J  plug  tapped  in  top  sheet  of 
furnace,  to  melt  and  give  warning  wher  the  water  falls 
below  it. 


GLOSSARY.  .  177 

Plunger. — The  solid  piston  of  a  pump,  and  pressing  only 
by  one  end  against  the  water. 

Ports. — Openings,  or  passages. 

Priming. -J^-The  passage  of  water,  along  with  the  steam, 
into  the  cylinders,  when  the  engine  is  working. 

Rocker  Shaft. — A  shaft  rocking  in  its  bearings. 

Reversing  Lever. — A  lever  in  reach  of  the  engineman, 
acting  upon  the  valve  motion,  and  to  change  the  direction 
of  the  progress  of  the  engine. 

Safety  Valve. — A  valve  on  the  boiler,  to  discharge  the 
eurplus  steam  generated,  above  what  is  required  for  the 
engine,  and  which  by  accumulating  would  endanger  the 
safety  of  the  machine. 

Slide.— See  Guide. 

Smoke-box. — A  chamber  at  forward  end  of  boiler,  where 
the  smoke  and  sparks  from  the  tubes  are  received  and  dis- 
charged through  the  sparker. 

Sparker,  or  Chimney. — A  pipe  to  discharge  the  smoke 
and  waste  steam,  and  surrounded  by  a  casing  to  retain  the 
sparks. 

Springs. — These  are  required  over  each  wheel  to  reduce 
shocks  and  jolts. 

Steam  Chest. — Box  on  top,  or  side  of  cylinder,  and  con- 
taining the  valve  to  admit  steam  on  the  piston. 

Steam  Pipe. — Pipe  entering  the  dome,  and  communi- 
cating with  the  steam  chests  through  two  branch  steam 
pipes  in  the  smoke-box. 

Stuffing-box. — See  Piston  Rod. — Used  in  all  situations 
where  a  rod  or  spindle,  having  any  end  motion,  requires 
to  be  made  steam  or  water  tight  around  same. 

Sub-Treasury. — A  receptacle  for  sparks.     Slightly  dif 


178  GLOSSARY. 

ferent  from  those  at  the  custom-house,  but  quite  as  ben* 
ficial. 

Stroke. — The  distance  travelled  by  the  piston  at  each 
period  of  its  motion. 

Tender. — A  separate  carriage,  to  carry  wood  and  water. 

Thimble. — A  tube  of  iron  or  steel. 

Throttle  Valve. — A  valve  in  the  dome,  and  closing  the 
mouth  of  the  steam  pipe. 

Trailing  Wheels. — A  pair  of  small  wheels,  placed  behind 
the  drivers,  when  but  one  pair  of  the  latter  is  used. 

Traction. — Differing  from  adhesion  in  this  :  The  adhe- 
sion is  the  power  of  the  engine  derived  from  the  weight  on 
its  driving  wheels  and  their  friction  on  the  rails  ;  while 
the  traction  is  also  the  power  of  the  engine,  but  derived 
from  the  pressure  of  the  piston  applied  through  the  crank 
and  radius  of  the  wheel.  These  two  elements  may  not 
always  be  the  same. 

Truck  Frame. — A  separate  frame,  supporting  four  or  six 
wheels,  and  turning  on  a  pintal,  independent  of  the  body 
of  the  engine  or  car. 

Tubes. — These  are  used  to  conduct  the  heat  from  the 
fire-box,  through  the  waste  of  the  boiler,  to  the  smoke-box. 
When  a  tube  is  so  large  as  to  require  to  be  made  of  plates, 
riveted  together,  it  is  called  a  flue. 

Valve. — Any  gate  or  fixture,  other  than  a  cock,  to  close  a 
steam  or  water  passage  about  an  engine.  The  main,  or 
port  valve,  which  admits  steam  directly  to  the  cylinders, 
is  a  block  with  a  recess  or  cavity  on  its  under  side.  The 
steam  passes  by  the  ends  of  the  valve  into  the  ports,  and 
the  motion  of  the  valve,  derived  from  the  eccentrics,  admits 
the  stea'n  at  the  proper  time. 


GLOSSARY.  179 

The  uses  of  the  cut-off  and  safety  valves  h.QVS  been  de- 
scribed. 

The  pump  valves  are  either  what  are  called  ball  valves, 
spindle  valves,  or  cup  valves.  The  check  valve  is  an  addi- 
tional valve  on  the  forcing  side  of  the  pump,  and  is  to  pre- 
vent all  danger  of  forcing  back  the  water  from  the  boiler 
into  the  pump  by  the  action  of  the  steam. 

Variable  Cut-off. — An  arrangement  to  alter  the  travel  of 
either  the  main,  or  cut-off  valve,  to  use  full  steam  through 
a  greater  or  less  distance  of  the  stroke. 

Variable  Exhaust. — An  arrangement  to  enlarge  or  con- 
tract the  blast  pipes. 

V-Hooks. — So  called  from  their  form  of  opening ; — much 
better  than  the  common  kind,  as  they  are  sure  to  catch  the 
pins,  and  for  this  reason  (though  an  old  idea)  are  coming 
into  general  use. 

Wliistle. — A  hollow  cup  made  to  allow  the  steam  to 
strike  its  lower  edge,  by  which  a  shrill  sound  is  obtained 
ft  r  signals. 


INDEX. 


PAGE 

ADHESION  of  Drivers 166 

Alteration  of  a  Ten-wheel  Engine  on  the  Northern  Road  122 

Anthracite,  cost  of. 114 

Fire-box  for  burning 116 

difficulties  met  in  the  use  of 117 

Angle  Iron 40 

Areas  of  Cylinders 154 

of  Chimney 50 

Ash  Pan 51 

Axles.     Crank,  and  mode  of  manufacture 72 

Truck 75 

Babbitt's  Metal.... 95 

Baltimore  and  Ohio  Railroad 107 

Bayley,  0.  W.,  Engine  by 120 

Blast  Pipe,  contraction  of. 66 

for  Coal  Engine 119 

Blow-off  Cocks 52 

Boilers,  details  of. 40 

Iron  for 39 

Bolts 94 

16  181 


182  INDEX. 

Cam  Shaft 85 

Calculations,  &c.  relative  to  the  Locomotive 127 

Capacity  of  Boilers 54,  141 

of  Tender  Tank 149 

Chilled  Wheels 70 

Chilled  Tires 71 

Chimney,  (see  Sparker.) 49 

Chests,  Steam ; 65 

Circumferences  of  Drivers 154 

Cleansing  greasy  wood-work 100 

Coal  Engine  by  Ross  Winans 110 

"John  Stevens," 120 

Experiments  on 113 

Connecting  Rods 80 

Composition  for  Packing  Rings 78 

Copper  Tube  Sheet. 43 

Cross  Head 80 

Crank  Axle 72 

Cylinders 62 

Outside 124 

Cut-off,  principle  of. 135 

to  estimate  amount  of  advantage  of. 140 

manner  of  working *. 85 

Damper , 51 

Description  of  the  Locomotive  Engine 24 

Dome 46 

Draft,  shutting  off  in  going  through  bridges 99 

Driving  Wheels 70,  173 

Eccentrics 174 

Engines,  details  of. 39.    95 

on  Baltimore  ana  Ohio  Road..:...  .    ,.     10'' 


INDEX.  183 

Engines  on  Fitchburg  Road 163 

by  Bury,  Curtis  &  Kennedy  .....  57 

by  Thacher  Perkins 58 

by  Taunton  Loc.  Mfg.  Co 55 

Equalizing  bar 73 

Estimate  for  Repair  Shop 163 

of  cost  of  Locomotive  Power 105 

Experiments  on  Coal  Engine , 112 

Explosions 158 

Evaporation  of  Water 133 

Fire-box. 2c 

Flues,  (see  Tubes) 42 

Frame 68 

Outside 76 

Freight  Engines .' 108 

Friction  of  Trains 130 

Fusible  Plug 160 

Gauge  Cocks 51 

Glass  Tubes '. 52 

of  Tracks 160 

Glossary .*.  171 

Grate 44 

Covering  up 44 

Area  of. 54 

Griggs,  G.  S.,  Engine  by 121 

Gray's  Variable  Cut-Off 87 

Gravity  of  Trains 131 

Hinkley's  Engines  .; ,. !    48 

Heating  Surface , 54,  143 

Hooks...  .    85 


184  INDEX. 

Iron,  for  boilers 39 

strength  of. 164 

Introduction 3 

India  Rubber  Springs 74 

Iron  Tender  Frame...,  77 


Jaws 69,  175 

"John  Stevens"  Passenger  Engine * 120 

Joints,  about  pump 95 

Putty  and  ground 65,    99 

Steam  Chest 65 

Steam  Pipe 65 

Keys 94 

Lap  of  Valve 90 

Latent  Heat 12 

Large  Drivers 123 

Level  of  Water 26 

Lead  of  Valve 31 

Link  Motion '. 85 

Locomotive,  details  of. 39,    96 

performance  of. 164 

cost  of. 157 

cost  of  power 105 

Shops  in  this  country 155 

Load  drawn  by  Engines 166 

Lowell  Machine  Shop,  Engines  by 54 

Mahogany  Dust  to  prevent  scales 99 

Middle  Tube  Sheet 43 

Mud-hole  Plugs 53 


INDEX.  185 

Norris,  E.  S.,  Engine  by 109 

Oil  used  on  Engines 105 

Open  Spring 75 

Outside  Frame 76 

Cylinders 124 

Passenger  Engines 108 

Packing 99,  176 

Composition  for  Rings 79 

Pipes 65 

Pistons 78 

Pintal 76,176 

Priming 18,177 

Properties  of  Steam 9 

Proportions  of  Boilers 54 

Power  of  Engines 128,  144 

Pumps 91 

Reversing  Apparatus 84 

at  full  speed 103 

Repair  Shops 162 

Rocker  Shafts 82 

Running  Engines 97 

Safety  Valves ... 47 

Sand-box,  use  of  wears  out  the  wheels 100 

Sand-box  on  Coal  Engine 114 

Setting  Valves  on  Locomotives.... 87 

Sharp,  Brothers  &  Co.'s  Link  Motion 86 

Slade  and  Currier's  experiments  and  report 112 

Slides.../. ; 80 

Slipping  the  Wheels 114 

16* 


I  1C  INDEX. 

Souther,  John,  Engine  by 54 

Engine  on  Fitchburg  Road 164 

Solid  Frame 68 

Spheroidal  State  of  Water 159 

Spring 73 

Sparker 49 

Steam,  properties  of. 9 

Steam  Carriage  on  the  Eastern  Counties  Line.... 125 

Stephenson's  Link  Motion ., 85 

Engine  by 56 

Estimate  of  power  expended  in  blast  pipe    66 

Strength  of  Boiler  Iron 164 

Stuffing  Boxes,  packing  for 100 

"Sub-Treasury" 50,  177 

Tables  and  Calculations 127 

Circumference  of  Drivers 153 

Hyperbolic  Logarithms 140 

Co-efficients  of  Speed  of  Piston 127 

Temperature  and  Elasticity  of  Steam 20 

Proportions  and  Dimensions  of  Engines...    54 

Performance  of  Engines 165 

Testing  Safety  Valves 100 

Ten-wheel  Engine  on  the  Northern  Road 122 

Throttle,  opening  for 98 

Tractive  Force  of  Engines 129 

Truck  Frame 75 

Tubes,  setting  do 42 

on  Coal  Engines 118 

Tires,  setting  and  removing  do 70 

Chilled 71 

Tyng's  Heating  Apparatus 61 

Valves 68,  178 


INDEX.  187 

Valve  Motion 83 

Stem 62 

Variable  Exhaust 98,  ITS 

Throw  of  Valve 85 

V-Hooks 85,179 

Water  Room  in  Boilers 54 

to  calculate 141 

Water  evaporated 133 

Bridges ; 117 

Waste  used 105 

Wheels 69 

Wrought  iron 71 

Chilled 70 

Whistle 48 

Winans,  Ross,  Engine  by , 110 

Coal  Engine  on  Worcester  Road Jl6 


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